ESSEN ELECTRONICS. (1987). SN-PC PC-XT USER MANNUAL. ESSEN ELECTRONICS.
Cita Chicago (17th ed.)ESSEN ELECTRONICS. SN-PC PC-XT USER MANNUAL. BOMBAY: ESSEN ELECTRONICS, 1987.
Cita MLA (9th ed.)ESSEN ELECTRONICS. SN-PC PC-XT USER MANNUAL. ESSEN ELECTRONICS, 1987.
Atenció: Aquestes cites poden no estar 100% correctes.