Copy paste a reference here and imported it to your reference collection.
RefFormer works correctly only with references of journals and NOT with references of books, book chapters or conference proceedings.
If you use Zotero or Mendeley you can import the reference to your collection (see help).

Copy paste a reference to this window, for example: Hamilton WD, 1964. The genetical evolution of social behavior I and II. J Theor Biol 7:1-52.