In this extensively revised and updated edition numerous concepts of graph theory are developed and applied to the formation of highly sparse structural matrices. For efficient handling, the nonzero entries of these matrices are given special patterns by powerful ordering algorithms created by the author. Presents ideas which are not only applicable to skeletal structures but can also be used equally for the analysis of other systems. Contains new concepts, methods and worked examples. Computer programs are included in the appendices to facilitate the use of several techniques featured in the text.