Perhaps you should try some spelling variations:
mathematical series » mathematical services, mathematical stories, mathematical species
mathematics series » mathematics species, mathematics studies, mathematics pieri's
plc financial » c financial, sec financial, etc financial
chapman » chaplain

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: chapman AND hall/plc financial ((mathematics series) OR (mathematical series)).
• Adding a wildcard symbol may retrieve word variants: chapman and hall/plc financial ((mathematics series) or (mathematical series))*.