Koegler, H. Concise Oxford dict. of ballet (Kochno, Boris; b. 1-3-04, Moscow; ballet librettist, writer on ballet; pen-name: Sobeka)
Sauget, H. La chatte, c1927 t.p. (M. Sobeka)
Opera Maddalena [SR] p1993 container (Boris Kohno)
en.wikipedia.org, March 2, 2016 (Boris Evgenievich Kochno or Kokhno (Russian: Борис Евгеньевич Кохно; 3 January 1904 - 8 December 1990) was a Russian poet, dancer and librettist; died in Paris)