APA (7th ed.) Citation

Koch, H. W. (1981). Computer work and computer trainee examinations. [Ken Books?].

Chicago Style (17th ed.) Citation

Koch, Harry Walter. Computer Work and Computer Trainee Examinations. [San Francisco, Calif.?]: [Ken Books?], 1981.

MLA (9th ed.) Citation

Koch, Harry Walter. Computer Work and Computer Trainee Examinations. [Ken Books?], 1981.