The Progressive reference library a new edition with extensive revisions, constituting a consolidation of the publications formerly on the market under the titles: International reference work and The new teachers' and pupils' cyclopaedia; a library of history, geography, biography, biology, literature, economics, civics, arts, sciences, discoveries, explorations, inventions, commerce, etc.; cyclopaedia of general and recent information. - Holst, Bernhart Paul. (Boone, Ia. Holst Pub., 1928)
Editor in chief: B.P. Holst.
On cover: With loose leaf revision service.
Subtitles of v.2-8 vary.
Vol.II has title: Loose leaf extension service.
Vols. 1-8 and 9-10 paged continuously.
Vols. 9-10 have title: Practical home and school methods.
Keywords: Encyclopedias and dictionaries