Cita APA (7th ed.)

Pen, J. (1966). Harmony and conflict in modern society. McGraw-Hill.

Cita Chicago (17th ed.)

Pen, Jan. Harmony and Conflict in Modern Society. New York: McGraw-Hill, 1966.

Cita MLA (9th ed.)

Pen, Jan. Harmony and Conflict in Modern Society. McGraw-Hill, 1966.