APA (7th ed.) Citation

(1988). IBM using disk operating system version 4.00. Perfect Bound Pub.

Chicago Style (17th ed.) Citation

IBM Using Disk Operating System Version 4.00. Quezon City: Perfect Bound Pub, 1988.

MLA (9th ed.) Citation

IBM Using Disk Operating System Version 4.00. Perfect Bound Pub, 1988.