?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Facta.bibl.u-szeged.hu%2F70936%2F&rft.title=On+discreteness+of+spectrum+of+a+second+order+differential+operator&rft.creator=+Labovskiy+Sergey+M.&rft.description=A+new+form+of+a+necessary+and+sufficient+conditions+for+the+discreteness+of+the+spectrum+of+singular+operator+%E2%88%92+1+%CF%81(x)+(p(x)u+0+0+%2C+%E2%88%92%E2%88%9E+%E2%89%A4+a+%E2%89%A4+x+%E2%89%A4+b+%E2%89%A4+%2B%E2%88%9E+is+obtained.+A+simpler+proof+of+the+necessity+is+obtained.&rft.date=2020&rft.type=Foly%C3%B3irat&rft.type=NonPeerReviewed&rft.format=full&rft.language=hu&rft.identifier=http%3A%2F%2Facta.bibl.u-szeged.hu%2F70936%2F1%2Fejqtde_2020_052.pdf&rft.identifier=+++Labovskiy+Sergey+M.%3A+++On+discreteness+of+spectrum+of+a+second+order+differential+operator.++(2020)+++