In past Word Ways issues, I have explored (Carrollian) word networks (Feb, May, Aug 1989), insertion-deletion networks (Aug 1990) and directed word chain networks (Aug, Nov 1991); I now study substitute-letter transposition (SLT) networks.
"Substitute-Letter Isogram Networks,"
Word Ways: Vol. 26
, Article 10.
Available at: http://digitalcommons.butler.edu/wordways/vol26/iss3/10