Done. Thanks. I did not succeed in finding it. Olivier On Tue, Jun 17, 2014 at 12:54 AM, <apovolot at gmail.com> wrote: > Hello Olivier - then you could probably incorporate the following from > A235644 > > > REFERENCES > Liang ding xiang, problem solving 93#, Bulletin of Mathematics (Wuhan), > 6(1992),41. ISSN 0488-7395. > >