  A Cayley-Sudoku table of a finite group G is a Cayley table for G subdivided
into uniformly sized rectangular blocks, in such a way that each group element
appears once in each block. They were introduced by J. Carmichael, K.
Schloeman, and M. B. Ward [CSW], who also gave three ways to construct them.
This paper has four aims. First, we review Constructions 1 and 2 of [CSW] and
uncover their unexpected heritage in the work of R. Baer and J. Denes. Next we
turn to some new instances of Construction 2 inspired by Baer, which answer an
open question in [CSW]. Third, we provide a very brief outline of recent
reinventions of special cases of Construction 1 in the literature. We conclude
with an invitation to seek out the heritage of Construction 3. Portions of this
paper appear in: Kady Hossner Boden and Michael B. Ward (2019) A New Class of
Cayley-Sudoku Tables, Mathematics Magazine, 92:4, 243-251, DOI:
10.1080/0025570X.2019.1613949
