APA استشهاد

Held , G. . .. (1994). Understanding Data Communications (4.). Prentice Hall of India.

استشهاد بنمط شيكاغو

Held , Gilbert. Understanding Data Communications. 4. New Delhi: Prentice Hall of India, 1994.

MLA استشهاد

Held , Gilbert. Understanding Data Communications. 4. Prentice Hall of India, 1994.