ignored (|author= suggested) (help)Negbennebor (2001). "The Freedom to Choose". Microeconomics. ISBN 1-56226-485-0.Parkin, Michael; Powell, Melanie; Matthews, Kent (2002). Economics. Harlow: Addison-Wesley. ISBN 0-273-65813-1.Perloff, J. (2008). Microeconomic Theory & Applications with Calculus. Pearson. ISBN 9780321277947.Pindyck; Rubinfeld (2001). Microeconomics (5th ed.). Prentice-Hall. ISBN 1405893400.Png, Ivan (1999). Managerial Economics. Blackwell. ISBN 9780631225164. සම්ප්‍රවේශය 28 February 2010.Ruffin, Roy J. (1988). Principles of Economics (3rd ed.). Glenview, Illinois: Scott, Foresman. ISBN 0-673-18871-X. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)Samuelson; Nordhaus (2001). Microeconomics (17th ed.). McGraw-Hill. ISBN 0070579539.Schumpeter, Joseph Alois; Schumpeter, Elizabeth Boody (1994). History of economic analysis (12th ed.). Routledge. ISBN 9780415108881. සම්ප්‍රවේශය 5 March 2010.Sloman, John (2006). Economics. Financial Ti