APA (7th ed.) Citation

THE HELIOS OPERATING.. (1989). The helios operating system: Perihelion software ltd. Prentice Hall.

Chicago Style (17th ed.) Citation

THE HELIOS OPERATING.. The Helios Operating System: Perihelion Software Ltd. New York: Prentice Hall, 1989.

MLA (9th ed.) Citation

THE HELIOS OPERATING.. The Helios Operating System: Perihelion Software Ltd. Prentice Hall, 1989.

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