Cita APA (7th ed.)

Levine, M. (1994). Effective problem solving (2nd ed.). Prentice Hall.

Cita Chicago (17th ed.)

Levine, Marvin. Effective Problem Solving. 2nd ed. Englewood Cliffs, N.J: Prentice Hall, 1994.

Cita MLA (9th ed.)

Levine, Marvin. Effective Problem Solving. 2nd ed. Prentice Hall, 1994.