Publications about Wildrik Botjes and his planetariums (with links where available)
- Bartelds, J. C. E., March 1930, in the Nieuw Nederlandsch Biografisch Woordenboek, eds. P. C. Molhuysen, P. J. Blok, and K. H. Kossmann, Leiden, part 8, pp. 188-189 "Botjes, Wildrik". [A two paragraph biographical synopsis of Wildrik Botjes (in Dutch).]
- Beekman, George W. E. 1985, Zenit, Volume 12., Nos. 7-8, pp. 250-251, "Botjes' Planetarium in Franeker". [An account of the donation of Botjes' second planetarium to the Eise Eisinga Planetarium (in Dutch).
- Havinga, Egbertus, van Wijk, Walter Emile, and D'Aumerie, J. F. M. G. 1928, 424 pp., "Planetarium-Boek: Eise Eisinga". [A book on planetariums published (in Dutch) on the occasion of the 100th anniversary of the death of Eise Eisinga. It includes description of the planetariums of Wildrik Botjes on pages 374 and following.]
- Kalamazoo Morning News, August 4, 1896, p. 8. "Wonderful Machine: Showing Complete Movement of Solar System" [A local newspaper account of the arrival of the Botjes Planetarium in North America].
- Menninga, Clarence 2013, presentation at the 2013 Annual Meeting of the American Scientific Affiliation, (July 19-22), "Wildrik Botjes Planetarium". [The link is a pdf of the presentation slides.]
- Menninga, Clarence 2013, Watch & Clock Bulletin Vol. 55/4, No. 404, (July-August), pp. 361-370. "A Miniature Planetarium Powered by a Chauncey Jerome Chronometer" (www.nawcc.org) [This article gives an overview of the operation of the planetarium and provides details on the restoration work done in 1988 and in 2012-2013.]
- Schulhof, Marc, May 18, 1992, Grand Rapids Press, "Calvin's gift planetarium is on display". [A local newspaper account of the arrival of the Botjes Planetarium at Calvin College and its restoration to working order by Clarence Menninga.]
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Written 8/29/2013, updated 9/8/2013 by Larry Molnar