Thomas von Randow explained

Thomas von Randow (26 December 1921 Breslau, Schlesien – 29 July 2009 Hamburg) was a German mathematician and journalist who published mathematical and logical puzzles under the pseudonym Zweistein in the "Logelei" column in Die Zeit. (After 2005 his column and pseudonym were continued by Bernhard Seckinger and Immanuel Halupczok.)

Publications

Many of his logic puzzles were published in the following books:

References

External links