"The Most Instructive Games of Chess Ever Played : 62 Masterpieces of Chess Strategy". Book by Irving Chernev, Game 18 : The Isolated Pawn (p. 81), 1965.
Howard Staunton (1873). “The Chess-player's Handbook: A Popular and Scientific Introduction to the Game of Chess, Exemplified in Games Actually Played by the Greatest Masters, and Illustrated by Numerous Diagrams of Original and Remarkable Positions”, p.34