I've been helping a relative to sell some of his content for SATs. He is from Venezuela and he writes in Spanish, but Español is not very common around Stacker News....so, now we can offer some Epubs in English.

The English books are the one with the BLUE book cover.

Here is the link to the store:
https://app.paywithflash.com/product-gallery/124?user=4ae89f2ee7f68dd79d07f6d4eea6fcd2329f80eb1c3cc09bdf8f5776116c446d