Before revision: I, RD-69-12STUDY OF TWO-FREQUENCY CAPTURE EFFECTS ON ILS RECEIVERS` MARCH 1969, Charles Manney , Wilcox, 1969.3.
After revision: I, FAA RD-69-12 STUDY OF TWO-FREQUENCY CAPTURE EFFECTS ON ILS RECEIVERS` MARCH 1969, Charles Manney , Wilcox, 1969.3.