Brown, G. M.; Walker, L. A. (1966). "Refinement of the structure of potassium heptafluoroniobate, K2NBF7, from neutron-diffraction data". Acta Crystallographica20 (2): 220–229. doi:10.1107/s0365110x66000458. Bibcode: 1966AcCry..20..220B.
Keller, O. L. (1963). "Identification of Complex Ions of Niobium(V) in Hydrofluoric Acid Solutions by Raman and Infrared Spectroscopy". Inorganic Chemistry2 (4): 783–787. doi:10.1021/ic50008a029.
Brown, G. M.; Walker, L. A. (1966). "Refinement of the structure of potassium heptafluoroniobate, K2NBF7, from neutron-diffraction data". Acta Crystallographica20 (2): 220–229. doi:10.1107/s0365110x66000458. Bibcode: 1966AcCry..20..220B.