Leonid Gerchikov, A. N. Ipatov, "Collective excitations in optical spectra of nanosize exciton and electron-positron droplets", Journal of Experimental and Theoretical Physics, vol. 119, pp. 891-901, 2014, [DOI: 10.1134/s1063776114110156] [IF: 0.88, SJR: 0.49]