Borwein is an authority in the area of mathematical optimization, and his book makes an important contribution to variational analysis
Provides a good introduction to the topic

and Notation.- Variational Principles.- Variational Techniques in Subdifferential Theory.- Variational Techniques in Convex Analysis.- Variational Techniques and Multifunctions.- Variational Principles in Nonlinear Functional Analysis.- Variational Techniques In the Presence of Symmetry.

Jonathan M. Borwein, FRSC is Canada Research Chair in Collaborative Technology at Dalhousie University. He received his Doctorate from Oxford in 1974 and has been on faculty at Waterloo, Carnegie Mellon and Simon Fraser Universities. He has published extensively in optimization, analysis and computational mathematics and has received various prizes both for research and for exposition.

Qiji J. Zhu is a Professor in the Department of Mathematics at Western Michigan University. He received his doctorate at Northeastern University in 1992. He has been a Research Associate at University of Montreal, Simon Fraser University and

University of Victoria, Canada.