APA

Simpson (Alan), . (1990). Dbase Iii Plus Programmers Reference Guide. : .

Chicago

Simpson (Alan), . 1990. Dbase Iii Plus Programmers Reference Guide. : .

Harvard

Simpson (Alan), . (1990). Dbase Iii Plus Programmers Reference Guide. : .

MLA

Simpson (Alan), . Dbase Iii Plus Programmers Reference Guide. : . 1990.