TY JOUR TI PROSPECTS OF IMPROVING THE EFFICIENCY OF HOP CULTIVATION CLUSTER OF THE CHUVASH REPUBLIC KW hops production efficiency KW hop-cluster cluster composition KW cluster approach. JO Vestnik of Kazan State Agrarian University AU Zaharov, A.I. AU Makushev, A.E. AU Vasil'eva, A.V. AU Kirillova, K.V. PY 2018 IS 13 PB Kazan state agrarian University