Boyvalenkov P. G., Dragnev P. D., Stoyanova M. M., Hardin D. P., Saff E. B. (2015) "Universal upper and lower bounds on energy of spherical designs", Dolomites Research Notes on Approximation, 8(Special_Issue), 51-65. DOI: 10.14658/PUPJ-DRNA-2015-Special_Issue-6