Zak, D. (2001). Programming with microsoft visual basic 6.0 enhanced edition. Course Technology.
Chicago-viite (17. p.)Zak, Diane. Programming with Microsoft Visual Basic 6.0 Enhanced Edition. Cambridge, Mass: Course Technology, 2001.
MLA-viite (9. p.)Zak, Diane. Programming with Microsoft Visual Basic 6.0 Enhanced Edition. Course Technology, 2001.
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