[1] L. BERAN: 
An approach to solvability in orthomodular lattices. Acta Univ. Carol. 13 (1972), 41-42. 
MR 0384629[3] E. L. MARSDEN, Jr.: 
The commutator and solvability in a generalized orthomodular lattice. Pacif. J. Math. 33 (1970), 357-361. 
MR 0263712 | 
Zbl 0234.06004