1. Klaus, M., Simon, B.: Binding of Schrödinger particles through conspiracy of potential Wells. Ann. Inst. Henri Poincaré30, 83–87 (1979)
2. Klaus, M.: Some remarks on Double-Wells in one and three dimensions. Ann. Inst. Henri Poincaré30, 405–417 (1981)
3. Holden, H., Høegh-Krohn, R., Johannesen, S.: The short range expansion, Adv. Appl. Math. (to appear)
4. Holden, H., Høegh-Krohn, R., Johannesen, S.: The short range expansion in solid state. Preprint Math. Inst. Oslo Univ.