1. ANSI/ISA-18.01-1979 (R2004), Annunciator Sequences and Specifications, p. 9.
2. ISA-RP77.60.02-2000, Fossil Fuel Power Plant Human-Machine Interface: Alarms, p. 9.
3. ANSI/ISA-84.00.01-2004-Part 2 (IEC 61511-2 Mod) – Functional Safety: Safety Instrumented.
4. 2004 Part 1 (IEC 61511-1 Mod) – Informative. Sections 9.4.2 and 9.4.3.
5. Alarm Systems: A Guide to Design, Management and Procurement. EEMUA, p. 105.