Counting $(1,\beta)$-BM relations and classifying $(2,2)$-BM groups
  In the first part, we prove that the number of $(1,\beta)$-BM relations is $3 \cdot 5 \cdot \ldots \cdot (2\beta + 1)$, which was conjectured by Kimberley. In the second part, we construct two isomorphisms between certain $(2,2)$-BM groups. This completes the classification of $(2,2)$-BM groups initiated by Kimberley and Robertson. 
Diego Rattaggi