[1] G. Birkhoff: Lattice theory. Providence, 1967. MR 0227053 | Zbl 0153.02501

[2] D. Duffus, W. Poguntke, I. Rival: Retracts and the fixed point problem for finite partially ordered sets. Canad. Math. Bull. 23 (1980), 231–236. MR 0576104

[3] D. Duffus, I. Rival: Retracts of partially ordered sets. J. Austral. Math. Soc., Ser. A 27 (1979), 495–506. MR 0542664

[4] D. Duffus, I. Rival, M. Simonovits: Spanning retracts of a partially ordered set. Discrete Math. 32 (1980), 1–7. MR 0588902

[5] D. Duffus, I. Rival: A structure theory for ordered sets. Discrete Math. 35 (1981), 53–118. MR 0620665

[6] J. Jakubík: Retracts of abelian lattice ordered groups. Czechoslov. Math. J. 39 (1989), 477–485. MR 1006313

[7] J. Jakubík: Retract varieties of lattice ordered groups. Czechoslov. Math. J. 40 (1990), 104–112. MR 1032363