I. N. Nwachukwu, C. E. Onyenweaku, J. C. Nwaru, and C. Paveliuc–Olariu, “Measuring the Degree of Market Power in the Export Demand for Nigerian Cocoa: An Analysis of Dutch Market”, JSDS, vol. 2, no. 3, pp. 94–103, Sep. 2011, doi: 10.22610/jsds.v2i3.658.