@article{JOLT_2004_14_1_a5,
     author = {B. E. Breckner and W. A. F. Ruppert},
     title = {On {Compactification} {Lattices} of {Subsemigroups} of {SL(2,} {R)}},
     journal = {Journal of Lie Theory},
     pages = {73--109},
     year = {2004},
     volume = {14},
     number = {1},
     doi = {10.5802/jolt.329},
     zbl = {1062.22017},
     url = {https://jolt.centre-mersenne.org/articles/10.5802/jolt.329/}
}