Editore: Norges Geologiske Undersokelse Nr. 168a, 1947, 71 pp. + folded map., 1947
Da: Eryops Books, Stephenville, TX, U.S.A.
Soft cover. Softcovers; ex-library; minor shelfwear w/ light creasing of corners of wraps and leaves; small tear on fore-edge of rear wrap; o/w in good condition.