The new historical-philological work "Ortsnamenbuch des Landes Oberösterreich" deals with all the official place names of the state of Upper Austria, ordered according to political districts. Volume 10 of the 12-volume series, of which volumes 1-4, 6-7 and 11 have already appeared, includes the 456 place names in the Urfahr-Umgebung political district of central Mühlviertel. It presents the etymologies of the names, including relevant details with regard to their formation, meaning and dialect-historical development, based on the earliest documents up to those of the 19th century as well as on the pronunciation of the local dialect. The spread of the most common place names can be seen on the 28 maps that are provided, which also mirror the course of settlement. The names found in the south ending in -ing and -heim are evidence of the oldest German settlements of the early Middle Ages, whereas the Germanized place names in the east are of Slavic origin. Names of the central areas that include "dorf" are of the High Middle Ages, and names including "schlag" in the north reflect the felling of the original forests. Particular name types, forenames and surnames found in the place names, as well as a general glossary of words are offered in the indices.