APA aipamena

Low, O., Low, O. C. o. p. E. c. f. f. s., & Low, O. A. n. c. o. p. E. c. w. p. a. t. p. (1986). Proficiency in English course (Rev. ed.). E. Arnold.

Chicago Style aipamena

Low, Ona, Ona. Certificate of proficiency English course for foreign students Low, and Ona. A new certificate of profociency English course with practice and test papers Low. Proficiency in English Course. Rev. ed. London: E. Arnold, 1986.

MLA aipamena

Low, Ona, et al. Proficiency in English Course. Rev. ed. E. Arnold, 1986.