a)HI: the h-index value was based on a list of publications ranked in descending order by the Times Cited count. The h-index indicates that there are h papers that have been cited at least h times. The H-index score from the WoSCC (1999–2018).
b)Average citations per item (ACPI): ACPI is the average number of cited articles for all items in the resultset. It is the sum of the times cited divided by the number of results in the timespan (1999–2018) .