TY  - BOOK
AU  - Levitan, B M
AU  - Sargsjan, I.S
TI  - Sturm-liouville and dirac operators
T2  - Mathematics and its applications (Soviet series) V.59
SN  - 0792309928
U1  - 515.35 
PY  - 1991///
CY  - Dordrecht
PB  - Kluwer
ER  -