Integral extension procedures in weakly σ-complete lattice-ordered groups, I M. Wilhelm (1984) Studia Mathematica
Isometries of multilattice groups Ján Jakubík, Milan Kolibiar (1983) Czechoslovak Mathematical Journal
Isomorphisms of real closed fields. Perović, Ž. (1995) Publications de l'Institut Mathématique. Nouvelle Série