Discrete spectrum of the periodic elliptic operator with a differential perturbation
Journées équations aux dérivées partielles (1994), article no. 14, 4 p. 
@incollection{JEDP_1994____A14_0,
     author = {Birman, Mikhail Sh.},
     title = {Discrete spectrum of the periodic elliptic operator with a differential perturbation},
     booktitle = {},
     series = {Journ\'ees \'equations aux d\'eriv\'ees partielles},
     eid = {14},
     pages = {1--4},
     publisher = {Ecole polytechnique},
     year = {1994},
     mrnumber = {1298685},
     language = {en},
     url = {http://www.numdam.org/item/JEDP_1994____A14_0/}
}
TY  - JOUR
AU  - Birman, Mikhail Sh.
TI  - Discrete spectrum of the periodic elliptic operator with a differential perturbation
JO  - Journées équations aux dérivées partielles
PY  - 1994
SP  - 1
EP  - 4
PB  - Ecole polytechnique
UR  - http://www.numdam.org/item/JEDP_1994____A14_0/
LA  - en
ID  - JEDP_1994____A14_0
ER  - 
%0 Journal Article
%A Birman, Mikhail Sh.
%T Discrete spectrum of the periodic elliptic operator with a differential perturbation
%J Journées équations aux dérivées partielles
%D 1994
%P 1-4
%I Ecole polytechnique
%U http://www.numdam.org/item/JEDP_1994____A14_0/
%G en
%F JEDP_1994____A14_0
Birman, Mikhail Sh. Discrete spectrum of the periodic elliptic operator with a differential perturbation. Journées équations aux dérivées partielles (1994), article  no. 14, 4 p. http://www.numdam.org/item/JEDP_1994____A14_0/

1. S. Alama, M. Avellaneda, P.A. Deift, R. Hempel, On the existence of eigenvalues of a divergence form operator A + λB in a gap of σ(A), Asymptotic Analysis 8 (4) (1994), 311-344. | MR | Zbl

2. M.Sh. Birman, Discrete spectrum of the periodic Schrödinger operator for non-negative perturbations, Operator Theory: Advances and Applications, vol. 70, Birkhäuser, Basel, 1994. | MR | Zbl