"This is a nicely written introduction to 'reality' and 'positivity' in rings, and besides students and researchers it can also be interesting for anyone who would like to learn more on positivity and orderings." (Vilmos Totik, Acta Scientiarum Mathematicarum, Vol. 68, 2002)

"A book on 'real algebra' that serves as an introduction to the subject in addition to the main theme of the text. . Well written with exercises for every chapter." (ASLIB Book Guide, Vol. 66 (11), 2001)