Home > WORDWAYS > Vol. 5 > Iss. 2 (1972)
Problem: From a doubled set of 21 different letters, to form 7 six-letter words such that any two taken at random shall have exactly one letter in common.
Lindon, J. A.
"The Seven Sixes Problem,"
Word Ways: Vol. 5
, Article 2.
Retrieved from: https://digitalcommons.butler.edu/wordways/vol5/iss2/2