Source:http://linkedlifedata.com/resource/umls/id/C0009085
MSH: A set of statistical methods used to group variables or observations into strongly inter-related subgroups. In epidemiology, it may be used to analyze a closely grouped series of events or cases of disease or other health-related phenomenon with well-defined distribution patterns in relation to time or place or both.,NCI: Methods for grouping objects into subsets such that those within each cluster are more closely related to one another than objects assigned to different clusters.