TY - CONF T1 - Two new indicators derived from the h-index for comparing citation impact: Hirsch frequencies and the normalised hirsch index JO - Proceedings of ISSI 2007 - 11th International Conference of the International Society for Scientometrics and Informetrics PY - 2007/01/01 AU - Levitt JM AU - Thelwall M ED - SP - 876 EP - 877 Y2 - 2025/05/22 ER -