Doubled Pawns, Chess Wiki

Doubled pawns are 2 pawns sharing the same File on the board. Like Isolated pawns, they are a hindrance because they block each other from moving. Usually doubled pawns do not have any other pawns defending them, so they are prime targets. They also have a limited range of attack. If there are three pawns stacked on a File, then they are called tripled pawns. Doubled pawns are often the results of trades or gambits.

How to Win at Chess (with Pictures) - wikiHow

Chess & Strategy: The Pawn Structure – Chess Chivalry

Rook (chess) - Wikiwand

Chess Glossary : Section C - Chess Game Strategies

How difficult is it to win a chess match without your pawns

history - Quintuple pawns / Interesting pawn structures - Chess

Chess.com - Wikipedia

Chess and Chess960 Wiki - backward pawn

Chess, Chess Wiki