Update README.md

Author: charlesgonzales

core-java/README.md

@@ -36,7 +36,6 @@
 - [A Guide to ThreadLocalRandom in Java](http://www.baeldung.com/java-thread-local-random)
 - [Compiling Java *.class Files with javac](http://www.baeldung.com/javac)
 - [A Guide to Iterator in Java](http://www.baeldung.com/java-iterator)
-- [The Trie Data Structure in Java](http://www.baeldung.com/trie-java)
 - [Introduction to Javadoc](http://www.baeldung.com/javadoc)
 - [Guide to the Externalizable Interface in Java](http://www.baeldung.com/java-externalizable)
 - [A Practical Guide to DecimalFormat](http://www.baeldung.com/java-decimalformat)
@@ -79,7 +78,6 @@
 - [Understanding Memory Leaks in Java](https://www.baeldung.com/java-memory-leaks)
 - [A Guide to SimpleDateFormat](https://www.baeldung.com/java-simple-date-format)
 - [SSL Handshake Failures](https://www.baeldung.com/java-ssl-handshake-failures)
-- [Implementing a Binary Tree in Java](https://www.baeldung.com/java-binary-tree)
 - [Changing the Order in a Sum Operation Can Produce Different Results?](https://www.baeldung.com/java-floating-point-sum-order)
 - [Java – Try with Resources](https://www.baeldung.com/java-try-with-resources)
 - [Abstract Classes in Java](https://www.baeldung.com/java-abstract-class)