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 ... [electronic resource] . — Boone, Ia., Chicago, Ill. [etc.] : Holst Pub. Co.,, 1928.. — 10 v. : superimposed front. (v.8) illus., plates (part col., 1 double, 1 superimposed) ports, maps. 26 cm.
Vols. 1-8 and 9-10 paged continuously. Subtitles of v. 2-8 vary. Vols. 9-10 have title: Practical home and school methods. Editor in chief: B.P. Holst.