MIL-A-27671B (AMENDMENT-3), MILITARY SPECIFICATION: AMPLIFIER-INDICATOR GROUP, ALTITUDE-VERTICAL SPEED A/A24G-11 (06-AUG-1986)
MIL-A-27671B (AMENDMENT-3), MILITARY SPECIFICATION: AMPLIFIER-INDICATOR GROUP, ALTITUDE-VERTICAL SPEED A/A24G-11 (06-AUG-1986).