Maven
--------
Official
https://maven.apache.org/
https://maven.apache.org/what-is-maven.html
https://maven.apache.org/guides/getting-started/index.html

Shorter stuff
https://maven.apache.org/guides/getting-started/maven-in-five-minutes.html
https://www.baeldung.com/maven
https://www.geeksforgeeks.org/devops/apache-maven/


Apache POI
-----------------
Official
https://poi.apache.org/

https://www.baeldung.com/apache-poi-slideshow