choices:
relevance: relevance
popularity: total number of checkouts
- callnumber: call number
+ call_number: call number
pubdate: date of publication
acqdate: date added
title: title
choices:
relevance: relevance
popularity: total number of checkouts
- callnumber: call number
+ call_number: call number
pubdate: date of publication
acqdate: date added
title: title