In the may 1983 Word Ways, Helen Motamen describes a word puzzle contest she won in which the object was to construct a five-by-five letter array containing a maximum number of three-letter, four-letter and five-letter words across and down.
Gordon, Leonard and Eckler, A. Ross
"Nested Word Squares,"
Word Ways: Vol. 27
, Article 9.
Available at: http://digitalcommons.butler.edu/wordways/vol27/iss1/9