Attributed to is a common phrase used in writing to express the source of a particular information or idea. However, for variety, there are other synonyms you can use. Some of these include "ascribed to," "assigned to," "credited to," "imputed to," "blamed on," "linked to" or "connected to." These synonyms may be used to bring a new level of variation and depth to your writing, while still expressing the same message. It is important, however, to ensure that whichever of these phrases used fits perfectly into the context of the sentence and does not alter the intended meaning of the sentence.