W. Langeraar The stability of Decca Patterns under various circumstances and the Influence of Time on that stability PDF (English)
H. L.G. Bencker Report concerning the preparation of the Third Edition of the General Bathymetric Chart of the Oceans PDF (English)
Twin Auxiliary Surveying Ships « H-2 » & « H-3 » of Navy Hydrographic Institute, Cadiz, Spain PDF (English)