1A. A. K. Majumdar  , 2Md. Rezaul Karim  , 3G. C. Ray  , 
    A Note on Efficiency and Proper Efficiency in Differentiable Multiobjective Programming,
    Pakistan Journal of Social Sciences,
    Volume 3,Issue 4,
    2005,
    Pages 614-616,
    ISSN 1683-8831,
    pjssci.2005.614.616,
    (https://makhillpublications.co/view-article.php?doi=pjssci.2005.614.616)
    Abstract: We give a suitable example to show that, for general nonlinear vector optimization problem, Kuhn-Tucker type theorem may be failed to hold true.
    Keywords: Efficiency;Differentiable;Multiobjective Programming;Nonlinear and Optimization