In the May 1984 issue of Word Ways, the editor presented Websterian words containing tetragrams consisting of all 24 permutations of the letter-sets AIRT, AIST, and AGIR. He commented "there may be additional letter-sets that can be fully permuted into tetragram-embeddable Websterian words" because of the incomplete nature of the Thomas-Kassler-Wooley legal tetragram list. Indeed there are; I exhibit below three more tetragram permutations.
"More Tetragram Permutations,"
Word Ways: Vol. 17
, Article 15.
Available at: http://digitalcommons.butler.edu/wordways/vol17/iss3/15