Saejung, Satit; Wongchan, Kanokwan - In: Mathematical Methods of Operations Research 73 (2011) 2, pp. 153-157
In this paper, we give a short and simple proof of the recent result of Ceng et al. (Math Methods Oper Res 67(3):375–390, <CitationRef CitationID="CR1">2008</CitationRef>). Copyright Springer-Verlag 2011