Held, G. (1987). IBM PC & PC XT: User's reference manual (2.).
Chicago Edition CitationHeld, Gilbert. IBM PC & PC XT: User's Reference Manual. 2. BPB Pubilications, New Delhi, 1987.
MLA Edition CitationHeld, Gilbert. IBM PC & PC XT: User's Reference Manual. 2. 1987.
Warning: These citations may not always be 100% accurate.