...the Miller Harris website? You can order from them online, and you can also see their international listing of dealers there as well.
For another durable, complex citrus I would definitely suggest Bigarade Concentree, though it is clearly focuses on bitter bigarade oranges rather than the citrus blend of Citron Citron. You can request a free sample on the editions de parfums website - they will mail it internationally.
Regardin Colonia: While classed as unisex, I don't imagine many of today's women, with their fruity floral fragrances going for this bracing, bitter masterpierce. I imagine that it will be quite refreshing once summer comes again.