Reciprocals of Odd Numbers adding to 1/Historical Note

Theorem
reports in his of $1997$ that this result was reported by Kierstead and Nelson in Volume $10$ of the, but no information has so far been found to back this up.

It is believed that Kierstead may be either or his twin brother, while Nelson is most likely to be.

It is reported in the various relevant pages in the On-Line Encyclopedia of Integer Sequences that this set was apparently discovered by S. Yamashita in $1976$, but once more corroborative evidence is hard to come by.