Loopgraafmortier Duits model H20 (Leichter Minenwerfer n/A) kaliber 7,58 cm met getrokken loop, op grondplaat met radaffuit Fire power : British army weapons and theories of war 1904-1945 / Shelford Bidwell and Dominick Graham dell contemporary classics guns of August / Barbara W. Tuchman oxford world's classics hardback collection Poetry of the First World War : an anthology / edited with an introduction and notes by by Tim Kendall