Molitierno, J: Applications of Combinatorial Matrix Theory t Graph

... this book works well as a reference textbook for undergraduates. Indeed, it is a distillation of a number of key results involving, specifically, the Laplacian matrix associated with a graph (which is sometimes called the 'nodal admittance matrix' by electrical engineers). ... Molitierno's book represents a well-written source of background on this growing field. The sources are some of the seminal ones in the field, and the book is accessible to undergraduates.
-John T. Saccoman, MAA Reviews, October 2012

The book owes its textbook appeal to detailed proofs, a large number of fully elaborated examples and observations, and a handful of exercises, making beginning graduate students as well as advanced undergraduates its primary audience. Still, it can serve as useful reference book for experienced researchers as well.
-Zentralblatt MATH