Hutchinson, J. (1967). Key to the families of flowering plants of the world (Rev. and enl. for use as a suppl. to The genera of flowering plants.). Clarendon Press.

Hutchinson, John. Key to the Families of Flowering Plants of the World. Rev. and enl. for use as a suppl. to The genera of flowering plants. Oxford: Clarendon Press, 1967.

Hutchinson, John. Key to the Families of Flowering Plants of the World. Rev. and enl. for use as a suppl. to The genera of flowering plants. Clarendon Press, 1967.