The document was written by an unknown author to the officials.

It was allegedly written by an unknown author in the 17th century.

But some think the books were written by an unknown author at a later date, sometime between 80 and 150.

It was written by an unknown author (or, less probably, several authors) between about 1320 and 1335.

It was created in verses by an unknown author at the beginning of the 14th century.

Daniel then attempts to look for other books by this unknown author but can find none.

Promotions are usually considered good investments when they call attention to a new or unknown author.

I'm hoping maybe the unknown author will think twice before focusing on human needs in such an article next time.

It was just a Christmas story from an unknown author, is the way he recalled the general reaction.

The unknown author probably used the same sources as Genesios.