An improved upper bound in a proper non-binary variance-balanced design

Block Designs: A Randomization Approach

“…There are several methods of constructing nonbinary block designs in the literature, for example, see John (1964), Murty and Das (1967), Das and Rao (1968), Dey (1970), Ceranka and Mejza (1979), Agarwal and Kumar (1986b), Jacroux and Majumdar (1989), Kageyama (1987aKageyama ( , 1991, Sinha and Kageyama (1991), Ghosh, Joshi and Kageyama (1993).…”