Wolfgang Köhler: (1929): An old pseudoproblem
Wolfgang Kohler, one of the founders of Gestalt psychology, explicates the epistemological position of Gestalt psychology in this article

Kohler's Work on Insight Learning
brief excerpt on Kohler's research from the book: The Animal Mind by J.L Gould & C. G. Gould

Introduction to Wolfgang Kohler: Mentality of Apes
Excerpted from Wolfgang's Kohler's book The Mentality of Apes (1925).

Wolfgang Köhler
Short bio and suggestions for further information.

A.S. Luchins & E.H. Luchins: Isomorphism in Gestalt theory
Comparison of Wertheimer's and Koehler's concepts; by Abraham S. Luchins and Edith H. Luchins (1999)

Kohler's objections to Thorndike's Puzzle Box approach
Excerpted from Wolfgang's Kohler's book The Mentality of Apes (1925).