Group #1 2000 paper (10618382) Group #2 2001 paper (11427891) Group #3 2002 paper (11854495) (Medline PMID) Group #2 2003 paper Yes Yes Yes 12522259 Group #5 2003 paper Yes Yes Yes 12831877 Group #6 2003 paper Yes Yes Yes 12897855 Group #7 2004 paper Yes Yes Yes 15321707 Group #8 2004 paper Yes Yes Yes 15447507 Group #3 2005 paper Yes Yes Yes 15663933 Group #9 2005 paper Yes Yes Yes 16002089 Group #7 2005 paper Yes Yes Yes 15882698 Group #10 2006 paper Yes Yes Yes 16453064 Group #1 2006 paper Yes No Yes 17043216 Group #11 2006 paper Yes Yes Yes 17012315 Group #6 2007 paper Yes Yes Yes 17108322

Table 1: Co-citations of three publications in a small list of related publications. Incidence of grouped-co-citation of 3 seminal papers in a particular field by 11 independent laboratories. Ten out of 11 groups cite the 3 seminal publications in a grouped-co-citation.