diff --git a/src/PhoneNumbers/DataFiles/AL.txt b/src/PhoneNumbers/DataFiles/AL.txt
index ad75adf7..df995323 100644
--- a/src/PhoneNumbers/DataFiles/AL.txt
+++ b/src/PhoneNumbers/DataFiles/AL.txt
@@ -1,5 +1,6 @@
 # References:
 # - https://www.itu.int/dms_pub/itu-t/oth/02/02/T02020000020002PDFE.pdf
+# - https://akep.al/wp-content/uploads/2021/08/GuidePlaniKombetarNumeracionit14012014.pdf
 N|||41000000-46999999|
 N|||21020000-21099999,21120000-21199999,21220000-21299999,21320000-21399999,21420000-21499999,21520000-21599999,21620000-21699999,21720000-21799999,21820000-21899999,21920000-21999999|
 N|||22200000-22999999,23200000-23999999,24200000-24999999,25200000-25999999,27200000-27999999,28200000-28999999,29200000-29999999|