Definitions for "Attributed"
It is the opinion of the person selling the item that it is from the person or factory it is attributed to, but it has not been proven.
Used to suggest a specific artist or period without guaranteeing the authenticity of the piece. The auctioneer / appraiser may not be able to confirm beyond a doubt as to who the artist or maker of a piece is.
In our opinion, probably a work of art by the artist.
when used following the author's name in the citation of a quotation, it means regarded as belonging to, written or said by, etc.; to regard as characteristic of a person or thing.  A quotation cited with an author's name followed by the word attributed was not necessarily said or written by that person but is commonly regarded as the author anyway because it seems to be in their style, something they would or could have said.  The main point in cases of this type of attribution is that the citation of the author is either not certain or admittedly incorrect.