TY JOUR TI RATIONAL PARAMETERS OF A MULTI-SPAN GREENHOUSE OF BUILDING PRODUCTION FOR SMALL FORMS OF MANAGEMENT KW multi-span greenhouse KW steel frame KW rational parameters of the frame JO Bulletin of Belgorod State Technological University named after. V. G. Shukhov AU Blazhnov, A.A. PY 2020 IS 5 PB Belgorod State Technological University named after V.G. Shukhov