\Bibitem{BogVas93} \by O.~V.~Bogopolskii, V.~A.~Vasil'ev \paper On the multiplicity of illumination of convex bodies by point sources \jour Mat. Zametki \yr 1993 \vol 54 \issue 4 \pages 12--18 \mathnet{http://mi.mathnet.ru/mzm2415} \mathscinet{http://mathscinet.ams.org/mathscinet-getitem?mr=1256602} \zmath{https://zbmath.org/?q=an:0813.52006} \transl \jour Math. Notes \yr 1993 \vol 54 \issue 4 \pages 987--991 \crossref{https://doi.org/10.1007/BF01210416} \isi{https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=Publons&SrcAuth=Publons_CEL&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=A1993NL76800016}