Quartz crystal controlled oscillators of assessed quality - Part 4: Sectional specification - Capability approval (IEC 60679-4:1997); German version EN 60679-4:1998— 18 стр.
A specification in the IEC quality assessment system for electronic components (IECQ) - Quartz crystal units - Part 1: Generic specification; identical with IEC 61178-1:1993
