Devido a Kolberg 1962 Kolberg, O. (1962), «Congruences for Ramanujan's function τ(n)», Arbok Univ. Bergen Mat.-Natur. Ser. (11), MR0158873, Zbl0168.29502
Devido a Wilton 1930 Wilton, J. R. (1930), «Congruence properties of Ramanujan's function τ(n)», Proceedings of the London Mathematical Society, 31: 1–10, doi:10.1112/plms/s2-31.1.1
Devido a Kolberg 1962 Kolberg, O. (1962), «Congruences for Ramanujan's function τ(n)», Arbok Univ. Bergen Mat.-Natur. Ser. (11), MR0158873, Zbl0168.29502