APA

W M., B . A D., . (1981). Purnell's Concise Encyclopedia. Berkshire: Purnell.

Chicago

W Michael, B . A Dempsey, . 1981. Purnell's Concise Encyclopedia. Berkshire: Purnell.

Harvard

W M., B . A D., . (1981). Purnell's Concise Encyclopedia. Berkshire: Purnell.

MLA

W Michael, B . A Dempsey, . Purnell's Concise Encyclopedia. Berkshire: Purnell. 1981.