1. Multi-set designs - designs having blocks with repeated elements;Assaf;Congressus Numerantium,1985
2. Balanced n-ary designs: a combinatorial survey and some new results;Billington;Ars Combinatoria,1984
3. Balanced ternary designs with block size three, any Λ and any R;Billington;Aequationes Mathematicae,1985
4. Designs with repeated elements in blocks: a survey and some recent results;Billington;Congressus Numerantium,1989
5. A list of balanced ternary designs with R⩽15, and some necessary existence conditions;Billington;Ars Combinatoria,1983