Ramanujan, Srinivasa (1962). «On certain arithmetical functions». Collected Papers. New York, NY: Chelsea. σελίδες 136–162.
Melfi, Giuseppe (1998). «On some modular identities». Number Theory, Diophantine, Computational and Algebraic Aspects: Proceedings of the International Conference held in Eger, Hungary. Walter de Grutyer & Co. σελίδες 371–382.