[3] J. Jakubík:
The mixed product decompositions of partially ordered groups. Czech. Math. J. 20, 1970, 184-206.
MR 0258705
[4] J. Jakubík:
Lexicographic product decompositions of a linearly ordered group. Czech. Math. J. 36, 1986, 553-563.
MR 0863187
[5] J. Jakubík:
Lexicographic products of partially ordered groupoids. Czech. Math. J. 14, 1964, 281-305. (In Russian.)
MR 0167558
[6] A. I. Maltsev:
On ordered groups. Izv. Akad. Nauk SSSR, serija matem. 13, 1949, 473-482. (In Russian.)
MR 0032645