Romanyuk, A. S., Романюк, А. С., & Романюк, А. С. (1993). The best trigonometric and bilinear approximations for functions of many variables from the classes $B^r_{p, \theta}$. II. Institute of Mathematics, NAS of Ukraine.
Chicago Style (17th ed.) CitationRomanyuk, A. S., А. С Романюк, and А. С Романюк. The Best Trigonometric and Bilinear Approximations for Functions of Many Variables from the Classes $B^r_{p, \theta}$. II. Institute of Mathematics, NAS of Ukraine, 1993.
MLA (8th ed.) CitationRomanyuk, A. S., et al. The Best Trigonometric and Bilinear Approximations for Functions of Many Variables from the Classes $B^r_{p, \theta}$. II. Institute of Mathematics, NAS of Ukraine, 1993.
Warning: These citations may not always be 100% accurate.