I have published some works that should be accounted for/cited here, in my opinion. See: Lee B. Croft, “People in Threes Going Up in Smoke and other Triplicities ” THE ROCKY MOUNTAIN REVIEW, Vol. 59, No. 2 (2005), pp. 29-49 and online through a password at ROCKY MOUNTAIN E-REVIEW at www.rmmla.org. Also is the older: Lee B. Croft, “Triplicity and Textual Iconicity: Russian Literature through a triangular Prism” in SYNTACTIC ICONICITY AND LINGUISTIC FREEZES: THE HUMAN DIMENSION (Marge E. Landsberg, ed.) Mouton de Gruyter, Berlin/NY, 1995, pp. 249-265…as well as many talks.
"Among three persons walking side by side, there must be one I can learn from."
Meaning: I'm very busy. For example, "I'd like to stay and help, but I've got things to do, places to go and people to see."
When three people are walking together, there must be a teacher for me.