This is: a softcover copy of "Gryzewskiego Katalog Polskich Znaczkow Pocztowych (Gryzewski's Catalog of Polish Postage Stamps 1949-50 ," a Polish-language catalog of Polish stamps from 1860 and from 1918 to 1949. This booklet of 80 pages is a rare resource for Polish philately. It was printed in Warsaw in 1949. Check the scans for details.