APA (7th ed.) Citation

Helal, A. H., & Weiss, J. W. (1988). International Library Cooperation. Essen Symposium (10th, Essen, West Germany, October 19-22, 1987).

Chicago Style (17th ed.) Citation

Helal, Ahmed H., and Joachim W. Weiss. International Library Cooperation. Essen Symposium (10th, Essen, West Germany, October 19-22, 1987). 1988.

MLA (9th ed.) Citation

Helal, Ahmed H., and Joachim W. Weiss. International Library Cooperation. Essen Symposium (10th, Essen, West Germany, October 19-22, 1987). 1988.

Warning: These citations may not always be 100% accurate.