a)Degree: the degree of a vertex is its most basic structural property and the number of its adjacent edges.
b)Estimated betweenness: the vertex and edge betweenness are (roughly) defined by the number of geodesics (shortest paths) going through a vertex or an edge .
c)H-index: the h-index value is based on a list of publications ranked in descending order by the Times Cited count. An index of h indicates that there are h papers that have been cited at list h times.
d)Average citations per item (ACPI): this is the average number of cited articles for all items in the result set. It is the sum of the times cited divided by the number of results in the timespan .