THE REX COLE JR. DETECTIVE STORIES 
By Gordon Chapman
Grosset & Dunlap

1. REX COLE JR., AND THE CRYSTAL CLUE
2. REX COLE JR., AND THE GRINNING GHOST

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Advertisement inside wrapper of The Bobbsey Twins at Snow Lodge, by Laura Lee Hope, Illustrated by ???. Grosset & Dunlap. New York. 1913