References

Albers, Josef. (1969) Search Versus Re-Search, Hartford (Conn.): Trinity College Press.

Gardner, Martin. (1980) Mathematical Games: Dr. Matrix, like Mr. Holmes, comes to an untimely and mysterious end, Scientific American, 243, No. 3, 20-24; 243, No. 4, 26B; 243, No. 6, 28.