25298 William Banks/C. Nevans/Carl Pomerance: A remark on Giuga's conjecture
and Lehmer's totient problem. Albanian J. Math. 3 (2009), 81-85.

25534 Avery Carr: On Lehmer's totient problem. Number Theory List November 11, 2014, 1p.

26652 R. Coleman: Some remarks on Euler's totient function. Internet 2012, 8p.

26653 Scott Contini/Ernie Croot/Igor Shparlinski: Complexity of inverting the Euler function.
Math. Comp. 75 (2006), 983-996.

26925 Paul Erdös: Some remarks on Euler's \phi function.
... (ca. 1945), 540-544.

26926 Paul Erdös: Some remarks on Euler's \phi function. Acta Arithm. 4 (1958), 10-19.

25368 Paul Erdös: Some remarks on the iterates of the \phi and \sigma functions.
Colloq. Math. 17 (1967), 195-202.

26656 Kevin Ford: The distribution of totients. El. Res. Ann. AMS 4 (1998), 27-34.

26654 Kevin Ford: The number of solutions of \phi(x)=m. Ann. Math. 150 (1999), 1-29.

26657 Tristan Freiberg/Carl Pomerance: A note on square totients. Internet 2014, 11p.

25380 D.Lehmer: On Euler's totient function. Bull. AMS 38/10 (1932), 745-751.

26924 Florian Luca/Carl Pomerance: On some problems of Makowski-Schinzel
and Erdös concerning the arithmetical functions \phi and \sigma.
Coll. Math. 92/1 (2002), 111-130.

26927 A. Makowski. On some equations involving functions \phi(n) and \sigma(n).
Am. Math. Monthly 67 (1960), 668-670.

25278 Jozsef Sandor/Borislav Crstici: Handbook of number theory II.
Springer 2005, 640p. Eur 141.

25277 Jozsef Sandor/Dragoslav Mitrinovic/Borislav Crstici: Handbook of
number theory I. Springer 2006, 640p. Eur 132.