MLA

Hallgren, Richard C. Interface Projects for the Apple Ii. Englewood Cliffs: Prentice Hall, 1982.

APA

Hallgren, R. C. (1982). Interface projects for the apple II. Englewood Cliffs: Prentice Hall.

Chicago

Hallgren, Richard C. Interface Projects for the Apple II. Englewood Cliffs: Prentice Hall, 1982.