diff --git a/pom.xml b/pom.xml
index 8d6413b..6dbc295 100644
--- a/pom.xml
+++ b/pom.xml
@@ -264,11 +264,11 @@
     <implementation.build>${scmBranch}@r${buildNumber}</implementation.build>
     <implementation.build.tstamp>${maven.build.timestamp}</implementation.build.tstamp>
 
-    <httpclient.version>4.5.10</httpclient.version>
+    <httpclient.version>4.5.12</httpclient.version>
     <httpcore.version>4.4.12</httpcore.version>
-    <owlapi.version>5.1.11</owlapi.version>
-    <poi.version>4.1.1</poi.version>
-    <rdf4j.version>3.0.0</rdf4j.version>
+    <owlapi.version>5.1.13</owlapi.version>
+    <poi.version>4.1.2</poi.version>
+    <rdf4j.version>3.1.2</rdf4j.version>
     <semargl.version>0.7</semargl.version>
     <slf4j.logger.version>1.7.30</slf4j.logger.version>
     <tika.version>1.24</tika.version>
@@ -334,17 +334,17 @@
       <dependency>
         <groupId>org.apache.httpcomponents</groupId>
         <artifactId>httpclient</artifactId>
-        <version>4.5.12</version>
+        <version>${httpclient.version}</version>
       </dependency>
       <dependency>
         <groupId>org.apache.httpcomponents</groupId>
         <artifactId>httpclient-cache</artifactId>
-        <version>4.5.12</version>
+        <version>${httpclient.version}</version>
       </dependency>
       <dependency>
         <groupId>org.apache.httpcomponents</groupId>
         <artifactId>httpmime</artifactId>
-        <version>4.5.12</version>
+        <version>${httpclient.version}</version>
       </dependency>
       <dependency>
         <groupId>org.apache.httpcomponents</groupId>
@@ -391,17 +391,17 @@
       <dependency>
         <groupId>org.apache.poi</groupId>
         <artifactId>poi</artifactId>
-        <version>4.1.2</version>
+        <version>${poi.version}</version>
       </dependency>
       <dependency>
         <groupId>org.apache.poi</groupId>
         <artifactId>poi-ooxml</artifactId>
-        <version>4.1.2</version>
+        <version>${poi.version}</version>
       </dependency>
       <dependency>
         <groupId>org.apache.poi</groupId>
         <artifactId>poi-scratchpad</artifactId>
-        <version>4.1.2</version>
+        <version>${poi.version}</version>
       </dependency>
       <dependency>
         <groupId>com.fasterxml.jackson.core</groupId>
@@ -424,87 +424,87 @@
       <dependency>
         <groupId>org.eclipse.rdf4j</groupId>
         <artifactId>rdf4j-model</artifactId>
-        <version>3.1.2</version>
+        <version>${rdf4j.version}</version>
       </dependency>
       <dependency>
         <groupId>org.eclipse.rdf4j</groupId>
         <artifactId>rdf4j-rio-api</artifactId>
-        <version>3.1.2</version>
+        <version>${rdf4j.version}</version>
       </dependency>
       <dependency>
         <groupId>org.eclipse.rdf4j</groupId>
         <artifactId>rdf4j-rio-languages</artifactId>
-        <version>3.1.2</version>
+        <version>${rdf4j.version}</version>
       </dependency>
       <dependency>
         <groupId>org.eclipse.rdf4j</groupId>
         <artifactId>rdf4j-rio-datatypes</artifactId>
-        <version>3.1.2</version>
+        <version>${rdf4j.version}</version>
       </dependency>
       <dependency>
         <groupId>org.eclipse.rdf4j</groupId>
         <artifactId>rdf4j-rio-binary</artifactId>
-        <version>3.1.2</version>
+        <version>${rdf4j.version}</version>
       </dependency>
       <dependency>
         <groupId>org.eclipse.rdf4j</groupId>
         <artifactId>rdf4j-rio-turtle</artifactId>
-        <version>3.1.2</version>
+        <version>${rdf4j.version}</version>
       </dependency>
       <dependency>
         <groupId>org.eclipse.rdf4j</groupId>
         <artifactId>rdf4j-rio-rdfxml</artifactId>
-        <version>3.1.2</version>
+        <version>${rdf4j.version}</version>
       </dependency>
       <dependency>
         <groupId>org.eclipse.rdf4j</groupId>
         <artifactId>rdf4j-rio-ntriples</artifactId>
-        <version>3.1.2</version>
+        <version>${rdf4j.version}</version>
       </dependency>
       <dependency>
         <groupId>org.eclipse.rdf4j</groupId>
         <artifactId>rdf4j-rio-nquads</artifactId>
-        <version>3.1.2</version>
+        <version>${rdf4j.version}</version>
       </dependency>
       <dependency>
         <groupId>org.eclipse.rdf4j</groupId>
         <artifactId>rdf4j-rio-n3</artifactId>
-        <version>3.1.2</version>
+        <version>${rdf4j.version}</version>
       </dependency>
       <dependency>
         <groupId>org.eclipse.rdf4j</groupId>
         <artifactId>rdf4j-rio-trix</artifactId>
-        <version>3.1.2</version>
+        <version>${rdf4j.version}</version>
       </dependency>
       <dependency>
         <groupId>org.eclipse.rdf4j</groupId>
         <artifactId>rdf4j-rio-rdfjson</artifactId>
-        <version>3.1.2</version>
+        <version>${rdf4j.version}</version>
       </dependency>
       <dependency>
         <groupId>org.eclipse.rdf4j</groupId>
         <artifactId>rdf4j-rio-trig</artifactId>
-        <version>3.1.2</version>
+        <version>${rdf4j.version}</version>
       </dependency>
       <dependency>
         <groupId>org.eclipse.rdf4j</groupId>
         <artifactId>rdf4j-rio-jsonld</artifactId>
-        <version>3.1.2</version>
+        <version>${rdf4j.version}</version>
       </dependency>
       <dependency>
         <groupId>org.eclipse.rdf4j</groupId>
         <artifactId>rdf4j-repository-sail</artifactId>
-        <version>3.1.2</version>
+        <version>${rdf4j.version}</version>
       </dependency>
       <dependency>
         <groupId>org.eclipse.rdf4j</groupId>
         <artifactId>rdf4j-sail-memory</artifactId>
-        <version>3.1.2</version>
+        <version>${rdf4j.version}</version>
       </dependency>
       <dependency>
         <groupId>org.eclipse.rdf4j</groupId>
         <artifactId>rdf4j-repository-api</artifactId>
-        <version>3.1.2</version>
+        <version>${rdf4j.version}</version>
       </dependency>
       <dependency>
         <groupId>com.github.jsonld-java</groupId>
@@ -522,22 +522,22 @@
       <dependency>
         <groupId>net.sourceforge.owlapi</groupId>
         <artifactId>owlapi-api</artifactId>
-        <version>5.1.13</version>
+        <version>${owlapi.version}</version>
       </dependency>
       <dependency>
         <groupId>net.sourceforge.owlapi</groupId>
         <artifactId>owlapi-rio</artifactId>
-        <version>5.1.13</version>
+        <version>${owlapi.version}</version>
       </dependency>
       <dependency>
         <groupId>net.sourceforge.owlapi</groupId>
         <artifactId>owlapi-parsers</artifactId>
-        <version>5.1.13</version>
+        <version>${owlapi.version}</version>
       </dependency>
       <dependency>
         <groupId>net.sourceforge.owlapi</groupId>
         <artifactId>owlapi-apibinding</artifactId>
-        <version>5.1.13</version>
+        <version>${owlapi.version}</version>
       </dependency>
       <!-- END: OWLAPI -->
 
@@ -550,7 +550,7 @@
       <dependency>
         <groupId>commons-io</groupId>
         <artifactId>commons-io</artifactId>
-        <version>2.6</version>
+        <version>${commons-io.version}</version>
       </dependency>
       <!-- END:  Apache Commons -->