Perhaps you should try some spelling variations:
"uni shells / http://id.loc.gov/authorities/names/n93002992" » "unix shells / http://id.loc.gov/authorities/names/n93002992", "hi shells / http://id.loc.gov/authorities/names/n93002992", "si shells / http://id.loc.gov/authorities/names/n93002992", "unhi shells / http://id.loc.gov/authorities/names/n93002992", "unsi shells / http://id.loc.gov/authorities/names/n93002992", "un_ shells / http://id.loc.gov/authorities/names/n93002992"
"uni shells / http://id.loc.gov/authorities/james/n93002992" » "unix shells / http://id.loc.gov/authorities/james/n93002992", "hi shells / http://id.loc.gov/authorities/james/n93002992", "si shells / http://id.loc.gov/authorities/james/n93002992", "unhi shells / http://id.loc.gov/authorities/james/n93002992", "unsi shells / http://id.loc.gov/authorities/james/n93002992", "un_ shells / http://id.loc.gov/authorities/james/n93002992"
"ii shells / http://id.loc.gov/authorities/names/n93002992" » "ii shell / http://id.loc.gov/authorities/names/n93002992", "hi shells / http://id.loc.gov/authorities/names/n93002992", "die shells / http://id.loc.gov/authorities/names/n93002992", "ihi shells / http://id.loc.gov/authorities/names/n93002992", "isi shells / http://id.loc.gov/authorities/names/n93002992", "i_ shells / http://id.loc.gov/authorities/names/n93002992"
"i shells / http://id.loc.gov/authorities/names/n93002992" » "hi shells / http://id.loc.gov/authorities/names/n93002992", "si shells / http://id.loc.gov/authorities/names/n93002992", "_ shells / http://id.loc.gov/authorities/names/n93002992"

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (((((("uni shells / http://id.loc.gov/authorities/names/n93002992") OR ("i shells / http://id.loc.gov/authorities/names/n93002992"))) OR ("ii shells / http://id.loc.gov/authorities/names/n93002992"))) OR ("uni shells / http://id.loc.gov/authorities/james/n93002992")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((((\"uni shells / http://id.loc.gov/authorities/names/n93002992\") OR (\"i shells / http://id.loc.gov/authorities/names/n93002992\"))) or (\"ii shells / http://id.loc.gov/authorities/names/n93002992\"))) or (\"uni shells / http://id.loc.gov/authorities/james/n93002992\"))".
• Removing quotes may allow a broader search: (((((( uni shells / http://id.loc.gov/authorities/names/n93002992 ) OR ( i shells / http://id.loc.gov/authorities/names/n93002992 ))) or ( ii shells / http://id.loc.gov/authorities/names/n93002992 ))) or ( uni shells / http://id.loc.gov/authorities/james/n93002992 )).
• Adding a wildcard symbol may retrieve word variants: (((((("uni shells / http://id.loc.gov/authorities/names/n93002992") OR ("i shells / http://id.loc.gov/authorities/names/n93002992"))) or ("ii shells / http://id.loc.gov/authorities/names/n93002992"))) or ("uni shells / http://id.loc.gov/authorities/james/n93002992"))*.