Supplement no.3 to Army/Air Operations, Pamphlet no.4. (Chapter 3). Carriage of Artillery Equipment by air. Section 8. Gun, Machine, Polsten 20 mm. Mark I on … Gun Drill (R.A. (A.A). Units) for 20-mm. Hispano, Polsten, and Oerlikon Machine Guns. (Provisional). WO 7399 - Engeland Voorschrift 26/GS Publications/1150 WO 7399 Handbook of the Gun, Machine, Polsten, 20 mm. MK. I. WO 808 - Engeland Voorschrift 26/Manuals/3351
