[2] J. Jakubík:
Konvexe Ketten in $\ell $-Gruppen. Časopis pěst. matem. 84 (1959), 53–63.
MR 0104740
[3] J. Jakubík: Direct product decompositions of $MV$-algebras. Czechoslovak Math. J. 44 (1994), 725–739.
[4] J. Jakubík:
On complete $MV$-algebras. Czechoslovak Math. J. 45 (1995), 473–480.
MR 1344513