  The Hirsch index or h-index is widely used to quantify the impact of an
individual's scientific research output, determining the highest number h of a
scientist's papers that received at least h citations. Several variants of the
index have been proposed in order to give more or less preference to highly
cited papers. I analyse the citation records of 26 physicists discussing
various suggestions, in particular A, e, f, g, h(2), h_w, h_T, \hbar, m, {\pi},
R, s, t, w, and maxprod. The total number of all and of all cited publications
as well as the highest and the average number of citations are also compared.
Advantages and disadvantages of these indices and indicators are discussed.
Correlation coefficients are determined quantifying which indices and
indicators yield similar and which yield more deviating rankings of the 26
datasets. For 6 datasets the determination of the indices and indicators is
visualized.
