Clark, Sydney P., 1929- Structure of the earth / Sydney P. Clark, Jr. - Englewood Cliffs, N.J. : Prentice-Hall, 1971. - xi, 131 p. : ill. ; 24 cm. Bibliography: p. 127. LCCN: 74-166213 //r87 Subjects--Topical Terms: Geology, Structural.Geophysics.