@book{Sydsæter_Strøm_Hammond_2016, address={Harlow, England}, edition={5th ed}, title={Essential mathematics for economic analysis}, url={https://ebookcentral.proquest.com/lib/bilibrary/detail.action?docID=5138875}, publisher={Pearson Education}, author={Sydsæter, Knut and Strøm, Arne and Hammond, Peter J.}, year={2016} }