Balanced ternary designs with block size three, any ... and any R. Elizabeth J. Billington (1985) Aequationes mathematicae
Bestimmung kostenoptimaler Parameter für den kontinuierlichen Stichprobenplan von DODGE. R. LUDWIG (1974) Metrika
Bounds on the Efficiency of the Residual Design of Extended BIB Designs. Sanpei Kageyama, Hiroshi Setoya (1993) Metrika