1981

White, H. D. & Griffith, B. C. (1981), 'Author cocitation: A literature measure of intellectual structure', Journal of the American Society for Information Science 32 , 163--171 .

1973

Small, H. (1973), 'Co-citation in the scientific literature: A new measure of the relationship between two documents', Journal of the American Society for Information Science 24 , 265--269 .