diff --git a/books/free-programming-books-langs.md b/books/free-programming-books-langs.md
index a680d96b4..dc39ad72a 100644
--- a/books/free-programming-books-langs.md
+++ b/books/free-programming-books-langs.md
@@ -1084,6 +1084,7 @@ Books on general-purpose programming that don't focus on a specific language are
 * [Learn Java for FTC](https://github.com/alan412/LearnJavaForFTC) - Alan Smith (PDF)
 * [Learning Java Language](https://riptutorial.com/Download/java-language.pdf) - Compiled from StackOverflow Documentation (PDF)
 * [Microservices Best Practices for Java](https://www.redbooks.ibm.com/redbooks/pdfs/sg248357.pdf) (PDF)
+* [Object-Oriented Programming in JavaTM Textbook](https://www.cs.southern.edu/halterman/oopj.pdf) - Richard L. Halterman (draft) (PDF) (CC)
 * [OOP - Learn Object Oriented Thinking & Programming](http://pub.bruckner.cz/titles/oop) - Rudolf Pecinovsky (PDF)
 * [Open Data Structures (in Java)](http://opendatastructures.org/ods-java.pdf) - Pat Morin (PDF) (CC BY)
 * [Playing with Java Microservices on Kubernetes and OpenShift](https://leanpub.com/playing-with-java-microservices-on-k8s-and-ocp) - Nebrass Lamouchi