"Unterwasserphotographie." . . "Photographie." . . . "Praktische Anleitung" . . . . . . "Images below : a manual of underground and flash photography" . . . "Handbooks and manuals"@en . "Handbooks and manuals" . . . . "Images below a manual of underground and flash photography"@en . . . . . . "Höhle." . . "Motiv (Kunst)" . .