1. W. de Sitter, A proof of the constancy of the velocity of light, in: KNAW, Proceedings, 15 II, 1912-1913, Amsterdam, 1913, pgs. 1297-1298
2. W. de Sitter, Assoc. R.A.S., On Einstein’s Theory of Gravitation, and its Astronomical Consequences, (MNRAS 1916), Vol. 76, No. 9
3. W. de Sitter, On the relativity of inertia. Remarks concerning Einstein's latest hypothesis, in: KNAW, Proceedings, 19 II, 1917, Amsterdam, 1917, pp. 1217-1225
4. A. Einstein and W. de Sitter, On the Relation Between the Expansion and the Mean Density of the Universe, (PNAS 1932), Vol. 18, No. 3, pgs. 213-214
5. W. de Sitter, On the magnitudes, diameters and distances of the extragalactic nebulae and their apparent radial velocities, (BAIN May 1930), Vol. 5, No. 185 pgs. 157-171