1. van den Baar, Ton. Nicolaas van Wijk : the man, his work (1880-1941). In: Groen, B.M., Hinrichs, J.P. & Vermeer, W.R. (red.). Nicolaas van Wijk (1880-1941): a collection of essays on his life and work: published on the occasion of the 75th anniversary of the founding of the chair for Balto-Slavic languages at Leiden University. Amsterdam: Rodopi, 1988, p. 9-41.