[RIVER CROSSING PUZZLE]. (A wolf, goat and cabbage problem). Sweden about mid 19th century.

SMITH, JOHN MACDONALD: A Practical Handbook of the Khond Language. Cuttack, Printed at the Orissa Mission Press, 1876.

KUNDÍ, SAWADA (Ed.) / SAWADA, SIICHIRO (Artist): Ch sen ko t jiki-sh Collection of antique Korean ceramics. Kyoto, Uns›do, Taisho 13 (1924).

CARROTHERS, JULIA DODGE: Japan's Year. Illustrated by Japanese Artists. Tokyo, T. Hasegawa, Meiji 38 (1905).

ROUTLEDGE, KATHERINE PEASE (Mrs. SCORESBY): The Mystery of Easter Island. The Story of an Expedition. London and Aylesbury 1919.