MIL-R-27521A (AMENDMENT-1), MILITARY SPECIFICATION: RECEPTACLE, FLYING BOOM, AERIAL REFUELING, GENERAL SPECIFICATION FOR (03-APR-1983)
MIL-R-27521A (AMENDMENT-1), MILITARY SPECIFICATION: RECEPTACLE, FLYING BOOM, AERIAL REFUELING, GENERAL SPECIFICATION FOR (03-APR-1983).