ZAHLAN, A.B. EXCITONS, MAGNONS AND PHONONS IN MOLECULAR CRYSTALS : PROCEEDINGS OF AN INTERNATIONAL SYMPOSIUM HELD AT THE PHYSICS DEPARTMENT OF THE AMERICAN UNIVERISTY OF BEIRUT, LEBANON : 15-18 JANUARY, 1968 - Cambridge Cambridge University Press, Cambridge 1968 Dewey Class. No.: 530.416 / ZAH/EX