Hewitt Robins чулуулаг бутлуурын техникийн үзүүлэлтүүд
No 21 Course, The First all National Service Course. Fleet Requirement Unit Training courses (1939) to No 12 (1945) Nos 2 4 Missing. Phot 2 (1947) to 26 (1957) (Includes some National Service Phots who did 16 of the 27 week course and qualified as Phot 3s) Missing. 4, 8,9,12,16, 21or 22, 24.