I have books on my itch.io page, and that’s a great place to buy them. https://aspeed.itch.io
But I do have an author page on Amazon too, if that’s more your thing: https://www.amazon.com/stores/Andrea-Speed/author/B00463DQV2?ref=ap_rdr&store_ref=ap_rdr&isDramIntegrated=true&shoppingPortalEnabled=true
I should be available on other sites as well, such as Kobo, and also in your local library. If not, request the books at your library! That always helps, and you don’y have to buy anything.