Cita APA (7a ed.)

Wickelgren, W. A. (1974). How to solve problems: Elements of a theory of problems and problem solving. W.H. Freeman and Company.

Cita Chicago Style (17a ed.)

Wickelgren, Wayne A. How to Solve Problems: Elements of a Theory of Problems and Problem Solving. San Francisco: W.H. Freeman and Company, 1974.

Cita MLA (9a ed.)

Wickelgren, Wayne A. How to Solve Problems: Elements of a Theory of Problems and Problem Solving. W.H. Freeman and Company, 1974.