Thanks! Why is does it end in -ых if статьи is genitive singular? (I'm not questioning your translation, I'm just curious)

я прочитал две замечательные статьи - is perfectly correct.

They're both correct, or only your version?

Only "две замечательные" is correct. Замечательных would be correct with masculine nouns. For example, "два замечательных отрывка"

Oh so gender is a factor. So the translation above is incorrect?

I checked with my professor and he said that with feminine nouns, -ых is allowed, but -ые is more common, so thanks, Elena. That actually wasn't even in the book.