1. S. Alaca and K. S. Williams, Introductory Algebraic Number Theory (Cambridge Univ. Press, New York, 2004).
2. GTM;H. Cohen,1993
3. C. T. Davis and B. K. Spearman, “The index of a quartic field defined by a trinomial $$x^4+ax+b$$,” J. Alg. Appl. 17 (10), 185–197 (2018).
4. R. Dedekind, “Über den Zusammenhang zwischen der Theorie der Ideale und der Theorie der höheren Kongruenzen,” Göttingen Abhandlungen 23, 1–23 (1878).
5. L. El Fadil, “On the index divisors and monogenity of number fields defined $$x^5+ax^3+b$$,” Quaestiones Math. 46, 1–11 (2023).