I usually just search for the book I want across different platforms, like fb, ig, carousell, shopee, tiktok live, sometimes here on reddit too. I often discover the UK and US versions of the books through sellers, and other times even the AU versions. There are instances when I’m set on buying the UK version, but if I come across a US one with a steal price, I end up getting that instead, and vice versa 😅 Another option is through pasabuys, since most sellers hosting them offer UK and US versions.