APA (7th ed.) Citation

SPSS, Inc., Chicago, Ill., & SPSS, I. (1990). SPSS categories. SPSS.

Chicago Style (17th ed.) Citation

SPSS, Inc., Chicago, Ill., and Inc SPSS. SPSS Categories. Chicago, Ill. [u.a.]: SPSS, 1990.

MLA (8th ed.) Citation

SPSS, Inc., Chicago, Ill., and Inc SPSS. SPSS Categories. SPSS, 1990.

Warning: These citations may not always be 100% accurate.