The cave twins /
by Lucy Fitch Perkins ; illustrated by the author.
Perkins, L. Fitch. (1916). The cave twins. Boston: Houghton Mifflin Co..
Perkins, Lucy Fitch, 1865-1937. The Cave Twins. Boston: Houghton Mifflin Co., 1916.
Warning: These citations may not always be complete (especially for serials).