Cita APA (7th ed.)

George Allen & Unwin Ltd. (1994). How things work: The universal encyclopedia of Machines Vol. II. Harper Collins Publications.

Cita Chicago (17th ed.)

George Allen & Unwin Ltd. How Things Work: The Universal Encyclopedia of Machines Vol. II. New delhi: Harper Collins Publications, 1994.

Cita MLA (9th ed.)

George Allen & Unwin Ltd. How Things Work: The Universal Encyclopedia of Machines Vol. II. Harper Collins Publications, 1994.