minor fix and improvement
diff --git a/SUMMARY.md b/SUMMARY.md
index a173a39..7afab8d 100644
--- a/SUMMARY.md
+++ b/SUMMARY.md
@@ -7,7 +7,7 @@
* [Engine](ch1_main_components/engine.md)
* [Engine Executor](ch1_main_components/engine_executor.md)
* [Artefacts](ch1_main_components/artefacts.md)
- * [Marvin Notebook Extension](ch1_main_components/components.md#marvin-notebook-extension)
+ * [Marvin Notebook Extension](ch1_main_components/notebook.md)
* [Installing Marvin](ch2_toolbox_installation/overview.md)
* [Ubuntu (Debian) Installation](ch2_toolbox_installation/ubuntu.md)
* [MacOS Installation](ch2_toolbox_installation/mac.md)
diff --git a/ch1_main_components/engine.md b/ch1_main_components/engine.md
index ee159e4..e2b77d4 100644
--- a/ch1_main_components/engine.md
+++ b/ch1_main_components/engine.md
@@ -1,3 +1,3 @@
# Engine
-The Engine is the Marvin application, the result of user's implementation, including code, datasets(artifacts), models, etc. We have some [engine examples on github](https://github.com/marvin-ai/marvin-public-engines) and you could install them like described in [Running an example engine](get_started/engine_examples.md)
\ No newline at end of file
+The Engine is the Marvin application, the result of user's implementation, including code, datasets(artifacts), models, etc. We have some [engine examples on github](https://github.com/marvin-ai/marvin-public-engines) and you could install them like described in [Running an example engine](ch3_get_started/engine_examples.md)
\ No newline at end of file
