Perhaps you should try some spelling variations:
"coal research laboratories" » "coal research laboratory", "doctoral research laboratories", "capital research laboratories"
"coal research library" » "coal research laboratory", "coal research summary", "doctoral research library", "capital research library"
"coal research libraries" » "doctoral research libraries", "capital research libraries"

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: (("coal research library") OR ((("coal research libraries") OR ("coal research laboratories")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"coal research library\") or (((\"coal research libraries\") OR (\"coal research laboratories\"))))".
• Removing quotes may allow a broader search: (( coal research library ) or ((( coal research libraries ) OR ( coal research laboratories )))).
• Adding a wildcard symbol may retrieve word variants: (("coal research library") or ((("coal research libraries") OR ("coal research laboratories"))))*.