diff --git a/pattern_matching/README.md b/pattern_matching/README.md
index f0c9440..29de767 100644
--- a/pattern_matching/README.md
+++ b/pattern_matching/README.md
@@ -1,5 +1,14 @@
 # Pattern Matching
 
+[Pattern matching algorithms](https://en.wikipedia.org/wiki/Pattern_matching) extend beyond strings, to include trees and other data structures. 
+
+🧭 Part of the pattern-matching group, in PWL
+
+* [Pattern Matching](../pattern_matching/README.md)
+* [Stringology](../pattern_stringology/README.md)
+
+----
+
 * :scroll: [Compiling Pattern Matching to good Decision Trees](compiling-pattern-matching-to-good-decision-trees.pdf) by Luc Maranget. Paper address the issue of compiling ML pattern matching to efficient decisions trees.
 * :scroll: [Extensible Pattern Matching in an Extensible Language](extensible-pattern-matching-extensible-language.pdf) by Sam Tobin-Hochstadt. Paper present a sophisticated pattern matcher for [Racket](http://racket-lang.org/), implemented as language extension using macros.
 * :scroll: [Warnings for pattern matching](warnings-for-pattern-matching.pdf) by Luc Maranget. Paper examine the ML pattern-matching anomalies of useless clauses and non-exhaustive matches.
diff --git a/pattern_stringology/README.md b/pattern_stringology/README.md
index b617ad0..098bcff 100644
--- a/pattern_stringology/README.md
+++ b/pattern_stringology/README.md
@@ -1,5 +1,13 @@
 # Stringology
 
+[Stringology](https://en.wikipedia.org/wiki/String_(computer_science)#String_processing_algorithms) refers to one of the various kinds of string processing algorithms. 
+
+
+🧭 Part of the pattern-matching group, in PWL
+
+* [Pattern Matching](../pattern_matching/README.md)
+* [Stringology](../pattern_stringology/README.md)
+
 ## External Papers
 
 * [A Taxonomy of Suffix Array Construction Algorithms](http://www.cas.mcmaster.ca/~bill/best/algorithms/07Taxonomy.pdf)