Patent GB103832: Improvements in Finishing Prisms or Lenses or Combinations of the same and in Apparatus therefor. Veröffentlicht am 5. Februar 1917, Erfinder: Frank Twyman, Alfred Green.
jstor.org
Lebenslauf unter: A. C. Menzies: Frank Twyman. 1876–1959. In: Biographical Memoirs of Fellows of the Royal Society. Band5, 1960, S.269–279, JSTOR:769291.
