A reversible word square is one in which every row can be read backwards, and every column upwards. Every word must be either a reversible word such as LANRET (TERNAL in reverse) or a palindrome, which is a special kind of reversible word. In this article, the term reversible word does not include palindromes. In general, counts include valid rotations and reflections.
Word Ways: Vol. 39
, Article 21.
Available at: http://digitalcommons.butler.edu/wordways/vol39/iss4/21