这是托福的句子：
One such painting is known as attributed to Rembrandt because of its style, and indeed the representation of the woman's face is very much like that of portraits known to be by Rembrandt.
句中is known as直接与attributed to连用，如果前者是作为一个固定短语使用，我感觉很困惑；如果不是的话，is known as attributed to 是不是is known as which is attributed to的缩写用法呢？