Cordes, R. (2004). Is grey literature ever used? Using citation analysis to measure the impact of GESAMP, an international marine scientific advisory body. Canadian Journal of Information and Library Science, 28, 45-65.
Citation analysis was used to measure the impact of GESAMP, the Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection, which since 1969 has published reports for the United Nations and seven of its agencies. Web of Science was used to search for citations to 114 publications, of which 15 are journal articles or books. Citations to grey literature can be difficult to locate and interpret, but two-thirds of the 1436 citations, in 1178 citing papers, are to grey literature items. The distribution of citations and self-citation are examined. Journal versions were cited more than corresponding reports. Core journals for GESAMP citations include seven environmental science journals and a social science journal. This paper confirms that citation searching can successfully measure the impact of organizations producing grey literature. Such publications can be very influential, diffusing widely from their source.