[1] Ya. Berkovich, D. Chillag and M. Herzog, Finite groups in which the degrees of the nonlinear irreducible characters are distinct, Proc. Amer. Math. Soc., 115 (1992) 955–959.

[2] Ya. Berkovich, I. M. Isaacs and L. Kazarin, Groups with distinct monolithic character degrees, J. Algebra, 216 (1999) 448–480.

[3] S. Dolfi, G. Navarro and P. H. Tiep, Finite groups whose same degree characters are Galois conjugate, Israel J. Math., 198 (2013) 283–331.

[4] S. Dolfi and M. K. Yadav, Finite groups whose non-linear irreducible characters of the same degree are Galois conjugate, J. Algebra, 452 (2016) 1–16.

[5] W. Feit, Characters of finite groups, W. A. Benjamin Inc., New York-Amsterdam, 1967.

[6] S. S. Gagola, Characters vanishing on all but two conjugacy classes, Pacific J. Math., 109 (1983) 363–385.

[7] M. Hall, The theory of groups, AMS Chelsea Publishing, Providence, Rhode Island, 1999.

[8] B. Huppert, Character theory of finite groups, Walter de Gruyter, Berlin, 1998.

[9] M. Loukaki, On distinct character degrees, Israel J. Math., 159 (2007) 93–107.

[10] D. Passman, Permutation groups, W. A. Benjamin Inc., New York-Amsterdam, 1968.

[11] G. Seitz, Finite groups having only one irreducible representation of degree greater than one, Proc. Amer. Math. Soc., 19 (1968) 459–461.

[12] H. Zassenhaus, Kennzeichnung endlicher linear Gruppen als Permutationsgruppen, Hamburg Abh., 11 (1936) 17–40.