Cita APA (7th ed.)

Helfman, E. (1963). Water for the world. Pyramid Books.

Cita Chicago (17th ed.)

Helfman, E. Water for the World. New York: Pyramid Books, 1963.

Cita MLA (9th ed.)

Helfman, E. Water for the World. Pyramid Books, 1963.

Atenció: Aquestes cites poden no estar 100% correctes.