APA (7th ed.) Citation

Microsoft Corporation. (1994). User's guide Microsoft MS-DOS 6.21 for the MS-DOS operating system. Microsoft.

Chicago Style (17th ed.) Citation

Microsoft Corporation. User's Guide Microsoft MS-DOS 6.21 for the MS-DOS Operating System. [Washington]: Microsoft, 1994.

MLA (9th ed.) Citation

Microsoft Corporation. User's Guide Microsoft MS-DOS 6.21 for the MS-DOS Operating System. Microsoft, 1994.