Notes on the primary, secondary and tertiary sectors.
http://businessstudiesonline.co.uk/GcseBusiness/TheoryNotes/Module%201/PdfNoPrint/04_Business_Activity.pdf
More notes: http://docs.paperless-school.com/PrimarySecondaryAndTertiaryBusinessSectors
BBC Bitesize notes: http://www.bbc.co.uk/schools/gcsebitesize/business/aims/aimsactivitiesrev2.shtml
BBC Bitesize test: http://www.bbc.co.uk/apps/ifl/schools/gcsebitesize/business/quizengine?quiz=aimsactivities;templateStyle=business
