Die Theorie der Parallellinien von Euklid bis auf Gauss; eine Urkundensammlung zur Vorgeschichte der nichteuklidischen Geometrie, in Gemeinschaft mit Friedrich Engel
A German source collection edited by Paul Stäckel and Friedrich Engel, published by Teubner in Leipzig in 1895, gathering documents on the parallel postulate from Euklid to Gauss for mathematicians and historians of non-Euclidean geometry. The plates are plain line diagrams — triangles, transversals, angle marks and dashed construction lines labelled with italic letters and numbered Fig. — usable as spare geometric linework set against Fraktur and roman text.
