From the reviews of the second edition:
"I have profitably used the book to apply constrained minimization procedures in the field of computational contact mechanics. I think it is not a secret that quite often books on mathematics are written from mathematicians for mathematicians. Hence it is quite hard for engineers to read and to extract valuable information from them. With this respect this book is a shining star. It presents the topics in a very precise but clear and understandable way."
(Giorgio Azvaris, Turin, Italy)
"I have the 1977 edition from my father's MIT days. I am a Mathematician and I can verify that the book written in 1977 is of the same style that good books have today. A book is not made obsolete because some new "elegant" terms arise."
(A reader from Greece)
"In this second edition ... David Luenberger focuses on practical optimization techniques. ... the book would be appropriate for graduate students or for self-study by professionals. ... I recommend the book for those who are familiar with elements of linear algebra ... . The book concludes with three short appendices ... and a bibliography and a short index. ... is intended for those who want to look deeply into optimization techniques, linear and nonlinear. ... will be useful to researchers, engineers, and graduate students." (Sergio Ubeda, Interfaces, Vol. 37 (1), 2007)