Let r be a positive
integer. A trigonometric series T of a single variable is said to be summable Rr
at 𝜃0 if the series obtained by r times formally integrating T has an r-th
symmetric derivative at 𝜃0. For even values of r, summability Rr has been
applied to double trigonometric series. We study here summability Rr, for
odd values of r, for double trigonometric series. We obtain a connection
between Bochner-Riesz summable series and series which are summable
Rr.