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@article{IVM_1967_4_a8, author = {I. D. Novikov}, title = {The spectra of quadratic operators of second quantization}, journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika}, pages = {64--68}, publisher = {mathdoc}, number = {4}, year = {1967}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/IVM_1967_4_a8/} }
I. D. Novikov. The spectra of quadratic operators of second quantization. Izvestiâ vysših učebnyh zavedenij. Matematika, no. 4 (1967), pp. 64-68. http://geodesic.mathdoc.fr/item/IVM_1967_4_a8/