[1] M. Anderson, T. Feil:
Lattice-Ordered Groups (Introduction). D. Reidel Publishing Company, 1988.
MR 0937703
[3] P. Conrad:
Lattice-Ordered Groups. Tulane Lecture Notes, Tulane University, 1970.
Zbl 0258.06011
[4] A.M.W. Class, W.C. Holland:
Lattice-Ordered Groups (Advances and Techniques). Kluwer Academic Publishers, 1989.
MR 1036072
[5] G. Gratzer:
Universal Algebra, 2 nd ed. Springer-Verlag, New York, 1979.
MR 0538623
[7] J. Martinez:
Free products in varieties of lattice ordered groups. Czechoslovak Math. J. 22(97) (1972), 535–553.
MR 0311536 |
Zbl 0247.06022
[8] J. Martinez:
Free products of abelian $l$-groups. Czechoslovak Math. J. 23(98) (1973), 349–361.
MR 0371770 |
Zbl 0298.06023
[9] J. Martinez (ed):
Ordered Algebraic Structure, 11–49. Kluwer Academic Publishers, 1989.
MR 1094821
[10] W.B. Powell, C. Tsinakis:
Free products of abelian $l$-groups are cardinally indecomposable. Proc. Amer. Math. Soc. 86 (1982), 385–390.
MR 0671199
[14] Dao-Rong Ton: Note on free abelian lattice groups (to appear).
[16] W.C. Weinberg: Free lattice-ordered abelian lattice groups. Math. Ann. 15 (1963), 187–199.