APA (7th ed.) Citation

(1994). Aspen Plus : user guide: User guide. Aspen Technology.

Chicago Style (17th ed.) Citation

Aspen Plus : User Guide: User Guide. [Cambridge, Mass.?]: Aspen Technology, 1994.

MLA (9th ed.) Citation

Aspen Plus : User Guide: User Guide. Aspen Technology, 1994.

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