Update README.md

Author: AndreG-P

README.md

@@ -57,4 +57,6 @@ We can see there are actually 6 distinguished left-hand sides in zbMATH:
 If you have `parallel` installed, you can speed up the process. For example:
 ```bash
 find . -type f | parallel 'grep "mrow(mi:E,mo:=,mrow(mi:m.*;[[:digit:]]*;..*;[3456789]$" {}' 2>/dev/null | awk '{print $1}'
+
+find . -type f | xargs -n 1 -P 32 gawk 'match($0, /^"mrow\(mi:E,mo:=,mrow\(mi:m.*;[[:digit:]]+;[[:digit:]]+;[[:digit:]][[:digit:]]+$/, arr) {print $1}'
 ```