Perhaps you should try some spelling variations:
regulations series » regulation series, relations series, regulations sciences
formation theory » information theory, deformation theory, formation theories
tax regulations » bank regulations, labor regulations
group formation » ground deformation
support group » support grant
export tax » export taxes, export day

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( export tax regulations series. ) or ( support group formation theory. ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( export tax regulations series. ) OR ( support group formation theory. ))*.