LEGO Architecture sets, while not easy to find, are available in a variety of places that are sure to be within your reach. First, we recommend you go to different online sales sites, such as Amazon, Mercado Libre and Ebay, where you can find several models available.
You can also go directly to physical Lego shops, where they will probably have most of the models in stock, especially the most recent ones, or you can go to the brand's website. You can also find these products in other toy stores such as Juguetron or in various department stores.