In the preceding Word Ways article, the editor defined and gave examples of various types of reversible word squares. An interesting and more complex variation of the reversible word square occurs when the main diagonals also form words which can be read from either the top or the base of the square. This adds a further four words to the totals possible in conventional reversible squares.
"Diagonal Reversible Word Squares,"
Word Ways: Vol. 14
, Article 7.
Available at: http://digitalcommons.butler.edu/wordways/vol14/iss4/7