Gaya APA

[Ed.], L, I, A, P, S. (1991). The medical directory 1991 (147. Ed). Harlow: Directory Pub.Association.

Gaya MLA

[Ed.], Longman, Industry, And, Publig, Service. "The medical directory 1991". 147. Ed Harlow: Directory Pub.Association, 1991. Text.