diff --git a/core-java/README.md b/core-java/README.md
index b40298abe4..cc3097006c 100644
--- a/core-java/README.md
+++ b/core-java/README.md
@@ -74,17 +74,14 @@
 - [CharSequence vs. String in Java](http://www.baeldung.com/java-char-sequence-string)
 - [Period and Duration in Java](http://www.baeldung.com/java-period-duration)
 - [Guide to the Diamond Operator in Java](http://www.baeldung.com/java-diamond-operator)
-- [Singletons in Java](http://www.baeldung.com/java-singleton)
 - [“Sneaky Throws” in Java](http://www.baeldung.com/java-sneaky-throws)
 - [OutOfMemoryError: GC Overhead Limit Exceeded](http://www.baeldung.com/java-gc-overhead-limit-exceeded)
 - [StringBuilder and StringBuffer in Java](http://www.baeldung.com/java-string-builder-string-buffer)
 - [Number of Digits in an Integer in Java](http://www.baeldung.com/java-number-of-digits-in-int)
-- [Proxy, Decorator, Adapter and Bridge Patterns](http://www.baeldung.com/java-structural-design-patterns)
 - [Creating a Java Compiler Plugin](http://www.baeldung.com/java-build-compiler-plugin)
 - [A Guide to the Static Keyword in Java](http://www.baeldung.com/java-static)
 - [Initializing Arrays in Java](http://www.baeldung.com/java-initialize-array)
 - [Guide to Java String Pool](http://www.baeldung.com/java-string-pool)
-- [Introduction to Creational Design Patterns](http://www.baeldung.com/creational-design-patterns)
 - [Quick Example - Comparator vs Comparable in Java](http://www.baeldung.com/java-comparator-comparable)
 - [Quick Guide to Java Stack](http://www.baeldung.com/java-stack)
 - [The Java continue and break Keywords](http://www.baeldung.com/java-continue-and-break)
@@ -116,8 +113,6 @@
 - [Comparing Strings in Java](http://www.baeldung.com/java-compare-strings)
 - [Guide to Inheritance in Java](http://www.baeldung.com/java-inheritance)
 - [Guide to Externalizable Interface in Java](http://www.baeldung.com/java-externalizable)
-- [The Observer Pattern in Java](http://www.baeldung.com/java-observer-pattern)
-- [Flyweight Pattern in Java](http://www.baeldung.com/java-flyweight)
 - [Object Type Casting in Java](http://www.baeldung.com/java-type-casting)
 - [A Practical Guide to DecimalFormat](http://www.baeldung.com/java-decimalformat)
 - [How to Detect the OS Using Java](http://www.baeldung.com/java-detect-os)
@@ -136,7 +131,6 @@
 - [Class Loaders in Java](http://www.baeldung.com/java-classloaders)
 - [Find Sum and Average in a Java Array](http://www.baeldung.com/java-array-sum-average)
 - [Java List UnsupportedOperationException](http://www.baeldung.com/java-list-unsupported-operation-exception)
-- [Service Locator Pattern](http://www.baeldung.com/java-service-locator-pattern)
 - [Type Erasure in Java Explained](http://www.baeldung.com/java-type-erasure)
 - [BigDecimal and BigInteger in Java](http://www.baeldung.com/java-bigdecimal-biginteger)
 - [Display All Time Zones With GMT And UTC in Java](http://www.baeldung.com/java-time-zones)
@@ -145,5 +139,5 @@
 - [Sending Emails with Java](http://www.baeldung.com/java-email)
 - [Introduction to SSL in Java](http://www.baeldung.com/java-ssl)
 - [Java KeyStore API](http://www.baeldung.com/java-keystore)
-- [Double-Checked Locking with Singleton](http://www.baeldung.com/java-singleton-double-checked-locking)
+- [Using Java Assertions](http://www.baeldung.com/java-assert)
 - [Guide to Java Clock Class](http://www.baeldung.com/java-clock)