Kageyama, Sanpei - In: Statistics & Probability Letters 11 (1991) 4, pp. 319-320
In a proper non-binary variance-balanced design with parameters [nu], b,r1,..., r[nu], k (< [nu]), [rho], a new stringent upper bound [rho] [less-than-or-equals, slant] {[nu](k-1)/[k([nu]-1)]} x (min ri) is derived, where [rho] is the unique non-zero eigenvalue of the C-matrix of the design