RSGB books without paying cross-pond postage?

[Robert E. Seastrom]

I'd like to get a copy of _Digital Modes for all Occasions_ by Murray
Greenman, ZL1BPU.  Amazon is out of stock (failed by the long tail!)
and doesn't know when they'll get more.  RSGB's web site lists it as
current.

Anyone have a favorite source of RSGB books on the north american
continent?

Thanks,

                                        ---rob