In his 1978 paper, Small suggested that, by citing a document and embedding the reference in textual commentary, authors impart meaning to these cited works. They become symbols of the concepts they contain (or which authors attach to them). The nature and variety of these concepts can be studied through a content analysis of the citation context. The present research builds on Small (1978) in several different ways. We focus on a single work – a book—and examine the range of concepts for which it has been cited. We use content analysis to create a taxonomy of cited concepts and examine the change in concept frequency over time. In addition, unlike Small, we also look at the diffusion of these concepts across the subject areas of the citing journal articles. The focus of our research is Frederic Brooks’ The Mythical Man-Month (MMM). Since its publication in 1975, it has been recognized as an important contribution to the general area of Software Project Management and other, related topics in Software Engineering. For our citation context analysis, we identified all articles citing one of the various editions of MMM from its initial publication in 1975 to the silver anniversary edition (1995). A taxonomy of cited concepts is currently under development and validation; the current draft contains 17 classes which occur with greater or lesser frequency across the set of citing articles. When the taxonomy is stabilized, we expect to report the frequency with which the different concept classes occur across the citing document set, their rise and fall in frequency across time, and the diffusion, over the 25 years, of the concepts for which MMM is cited into the subject areas outside of Software Engineering proper.