Cita APA (7a ed.)

Ullrich, R. A. (1981). Motivation methods that work. Prentice-Hall.

Cita Chicago Style (17a ed.)

Ullrich, Robert A. Motivation Methods That Work. Englewood Cliffs, N.J.: Prentice-Hall, 1981.

Cita MLA (9a ed.)

Ullrich, Robert A. Motivation Methods That Work. Prentice-Hall, 1981.