@incollection interpreted as @book

Hello,
When importing from a bibtex file into drupal, "@incollection" is interpreted as "@book" and the booktitle field is lost (or it passes into the series field if "series" does not appear in the bibtex file already). Is this the normal behaviour? As far as I've ssen, an 'incollection' is normaly a part of a book with its own title (therefore more of an "@inbook") and the booktitle is a required field.
Best regards,
Sorina