THE HELIOS OPERATING.. (1989). The helios operating system: Perihelion software ltd. Prentice Hall.
Cita Chicago (17th ed.)THE HELIOS OPERATING.. The Helios Operating System: Perihelion Software Ltd. New York: Prentice Hall, 1989.
Cita MLA (9th ed.)THE HELIOS OPERATING.. The Helios Operating System: Perihelion Software Ltd. Prentice Hall, 1989.
Atenció: Aquestes cites poden no estar 100% correctes.