APA Style

Held, G. (1991). Understanding data communications : From fundamentals to networking / Gilbert Held (1). Chichester: John Wiley & Sons.

MLA Style

Held, Gilbert. "Understanding data communications : From fundamentals to networking / Gilbert Held". 1 Chichester: John Wiley & Sons, 1991. Textbook ห้องสมุดทั่วไป.