J. M. Kilt 19.9-Metre Survey Launch of the Danish Administration of Navigation and Hydrography PDF (English)
J. M. Barbier, M. Chaumet-Lagrance, C. Fourcassies Sounding Data Processing by Mini-Computer PDF (English)
G. Zickwolff The Advantages of Stereographic Projection: Charts 2812 and 2813 of the "Deutsches Hydrographisches Institut" (DHI) PDF (English)