Symphony.

Have a field like behavior of Tag Field (if not exist save the new data and show below the field in next use) but can select one item only.

It's for a field I need to citation author (authors) but I want not need input the author in another section first to have it in a select. Make sense?

Hmm,

You can possibly use Subsection Manager. Whilst it links to another section if you use the right Options (allow creation of new items) you can create the new Authors, with all the date from the article section. So no need to create author before.

I think this will solve the problem you have, note that with subsection manager you can also search, so if you have a lot of authors it is a very good way to work.

PS. I am assuming that Authors are not Symphony authors but custom names inserted like tags.

Yes, thanks @gunglien I will try. I used subsection manager to images in other project.

Bests.