Kindle Self publishing amazon Malta

If I started a business related to Self Publishing Kindle Amazon.
(http://amazon.com/), USA)

Do you know in Malta how the royalties are taxable? I heard is 10%.

Do you know someone who is doing the same business in Malta about it? You can find all the info about what I am speaking about here:

https://kdp.amazon.com/en_US/help/topic/G201723290

If I receive royalties directly for the books sold, should I declare them in which way?
Thank you
Libero