Thanks for your question.
Theodore Tihansky is not referenced in Who's Who in American Art. I
checked through several editions as well as in Biography and Genealogy
Master Index (which indexes the publication) and he was not listed.
"Who's Who in American Art" New Jersey: Marquis Who's Who, 2002.
There are a few references to him on various web sites, that provide
some background information, specifically:
Newport Art Museum/Theodore Tihansky: Diary of an Artist
Theodore Tihansky (resume)
I also looked through some other standard reference works such as
Grove Dictionary of Art, but again, did not see Tihansky covered.
Biography and Genealogy Master Index
Grove Dictionary of Art
Who's Who in American Art
I hope this answers your question. If you require additional
information or if the links do not work, please ask for clarification
and I will do my best to assist you.