Title: Gemma Frisius, Tycho Brahe and Snellius and their triangulations.
Authors: Haasbroek, N. D.
Publisher: Rijkscommissie voor Geodesie [Delft, W. D. Meinema]
Year: 1968
Subjects: Gemma,; Brahe, Tycho,; Snellius, Willebrord,; Triangulation.