Knuth, Donald (1968), The Art of Computer Programming, 1, Addison Wesley, стр. 100, ISBN978-81-7758-754-8, „Before Fibonacci wrote his work, the sequence Fn had already been discussed by Indian scholars, who had long been interested in rhythmic patterns... both Gopala (before 1135 AD) and Hemachandra (c. 1150) mentioned the numbers 1,2,3,5,8,13,21 explicitly [see P. Singh Historia Math 12 (1985) 229–44]" p. 100 (3d ed)...”
Knuth, Donald (2006), The Art of Computer Programming, 4. Generating All Trees – History of Combinatorial Generation, Addison–Wesley, стр. 50, ISBN978-0-321-33570-8, „it was natural to consider the set of all sequences of [L] and [S] that have exactly m beats. ...there are exactly Fm+1 of them. For example the 21 sequences when m = 7 are: [gives list]. In this way Indian prosodists were led to discover the Fibonacci sequence, as we have observed in Section 1.2.8 (from v.1)”
doi.org
Singh, Parmanand (1985), „The So-called Fibonacci numbers in ancient and medieval India”, Historia Mathematica, 12 (3): 229—44, doi:10.1016/0315-0860(85)90021-7