Citations: Anonym 1937-1951: [Hopping, R.] Proceedings of the Entomological Society of British Columbia, N. S., Victoria 38, S. 3, Ziegler
Anonym 1942: [Hopping, R.] Entomological News , Philadelphia 53, S. 60, B15 10004
Anonym 1942: [Hopping, R.] Annals of the Entomological Society of America, Columbus/Ohio 35, B15 10270, pp. 124
Blaisdell, F. E. 1942: [Hopping, R.] The Pan-Pacific Entomologist, San Francisco 18 (1-3), B15 10463
Horn, W. 1938: [Hopping, R.] Arbeiten über morphologische und taxonomische Entomologie aus Berlin-Dahlem, Berlin 5 (2), B15 10838, pp. 187
Leech, H. B. 1940: [Hopping, R.] The Coleopterists' Bulletin, Washington 2, S. 56-57, B15 11200
Osborn, H. 1937: Fragments of Entomological History Including Some Personal Recollections of Men and Events. 1 Columbus, Ohio, Published by the Author, 1-394 S., B15: 6024, pp. 266
Osborn, H. 1946: Fragments of Entomological History Including Some Personal Recollections of Men and Events. 2 Columbus, Ohio, Published by the Author, 1-232 S., B15: 6024, pp. 91