A note on barely transitive permutation groups satisfying m i n - 2 M. Kuzucuoğlu (1993) Rendiconti del Seminario Matematico della Università di Padova
A theorem on doubly transitive permutation groups with application to universal algebras G. Grätzer (1964) Fundamenta Mathematicae
Autormorphism groups of countable highly homogeneous partially ordererd sets. A.M.W. Glass, S.H. McCleary, M. Rubin (1993) Mathematische Zeitschrift