@article{CC_2005_34_3_a13,
     author = {Nazarov, Serguei A. and Soko{\l}owski, Jan},
     title = {Self-adjoint extensions of differential operators and exterior topological derivatives in shape optimization},
     journal = {Control and Cybernetics},
     pages = {903--925},
     publisher = {mathdoc},
     volume = {34},
     number = {3},
     year = {2005},
     zbl = {1167.49330},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CC_2005_34_3_a13/}
}