This series, consisting of 26 volumes, was in print from 1934 through 1955. Volumes #1-8 were originally published by A.L Burt and later reprinted by Grosset & Dunlap. Volumes #1 - 5, and #7-23 were published by G&D. Volumes 24 - 26 were published by Clover Books. The sixth volume of this series, Beverly Gray at the World's Fair, went out of print when the series moved from A.L. Burt to Grosset & Dunlap and is the one of the scarcest of series books. Volumes seven and eight, were re-numbered accordingly and reissued by G&D.