L. D. Landau and S. I. Pekar, Effective mass of a polaron, Zh. Eksp. Teor. Fiz. 18, 419–423 (1948) [in Russian], English translation: Ukr. J. Phys. , Special Issue, 53, pp. 71–74 (2008), "Archived copy"(PDF). Archived from the original(PDF) on 2016-03-05. Retrieved 2016-08-10.{{cite web}}: نگهداری یادکرد:عنوان آرشیو به جای عنوان (link)
web.archive.org
L. D. Landau and S. I. Pekar, Effective mass of a polaron, Zh. Eksp. Teor. Fiz. 18, 419–423 (1948) [in Russian], English translation: Ukr. J. Phys. , Special Issue, 53, pp. 71–74 (2008), "Archived copy"(PDF). Archived from the original(PDF) on 2016-03-05. Retrieved 2016-08-10.{{cite web}}: نگهداری یادکرد:عنوان آرشیو به جای عنوان (link)
