@article{AMBP_1996__3_1_165_0,
     author = {Van Casteren, Jan A.},
     title = {On differences of self-adjoint semigroups},
     journal = {Annales math\'ematiques Blaise Pascal},
     pages = {165--188},
     publisher = {Laboratoires de Math\'ematiques Pures et Appliqu\'ees de l'Universit\'e Blaise Pascal},
     volume = {3},
     number = {1},
     year = {1996},
     mrnumber = {1397331},
     zbl = {0857.47027},
     language = {en},
     url = {http://www.numdam.org/item/AMBP_1996__3_1_165_0/}
}