Alsina, Claudi Norm derivatives and characterizations of inner product spaces/ Claudi Alsina, Justyna Sikorska and M. Santos Tomas. - Singapore: World Scientific, c2010. - x, 188 p.: ill.; 24 cm. Includes bibliographical references (p. 179-185) and index. ISBN: 9789814287265 9814287261 LCCN: 2010277952 Subjects--Topical Terms: Normed linear spaces.Inner product spaces. Dewey Class. No.: 515.733 / A461n