"This is an extraordinarily thorough and compact primer on special and general relativity written and translated from the Spanish by astrophysicist Ferraro (Institute of Astronomy and Space Physics, Universidad de Buenos Aires). It is a remarkable resource for intermediate and advanced undergraduates, as it introduces the more difficult mathematics with a minimum of formalism. . Summing Up: Highly recommended. Lower-division undergraduates through faculty." (P. D. Skiff, CHOICE, Vol. 45 (5), January, 2008)

"The author succeeds in his undertaking to present the special theory of relativity and a brief introduction to general relativity . . The style of the book is fresh and the author, paying attention to details, tries also to explain the material in his own words . . the pedagogical approach is the strength of this book by Ferraro. . suitable for readers who just want to get acquainted with the subject. The inclusion of the cosmological constant into the discussion seems timely." (Marek Nowakowski, Mathematical Reviews, Issue 2008 k)

"Ferraro gives a solid treatment of Special Relativity. . the book meets its aim to serve students following an introductory course on Relativity . . I consider the historical approach to be a plus for this overall sound text on Relativity." (Sylvia Wenmackers, Physicalia Magazine, Vol. 30 (4), 2008)

"In this 310-page text with 5 appendices there are 149 references in addition to 22 cited papers, 11 complements, 108 figures . . Plenty of derivations, explanations, margin and foot notes here make the whole book extremely purposeful and study friendly for any earnest seeker of inspired factual knowledge of the fundamental aspects of the relativity theories which are undoubtedly of great importance to all. The work can quite effectively serve as a valuable text book for the students and the researchers . ." (Paninjukunnath Achuthan, Zentralblatt MATH, Vol. 1157,2009)