1. M. Aigner and G. Prins (1971) Uniquely partially orderable graphs, J. London Math. Soc. (2) 3, 260–266. MR 43 #1866.
2. J.C. Arditti and H.A. Jung (1980) The dimension of finite and infinite comparability graphs, J. London Math. Soc. (2) 21, 31–38.
3. H. Buer and R.H. Möhring (1983) A fast algorithm for the decomposition of graphs and posets, Math. Oper. Res. 8, 189–194.
4. B. Dushnik and E.W. Miller (1941) Partially ordered sets, Amer. J. Math. 63, 600–610. MR 3, p.73.
5. N.D. Filippov (1968a) σ-isomorphisms of partially ordered sets (Russian), Ural. Gos. Univ. Mat. Zap. 6, 71–85. MR 42 #4452.