by Mihelis, G., Grigoroudis, E., Siskos, Y., Politis, Y., Malandrakis, Y.
Published in European journal of operational research (16.04.2001)

by Politis, Y., Siskos, Y.
Published in European journal of operational research (01.07.2004)

by Siskos, Y, Politis, Y, Kazantzi, G
Published in Operational research (01.01.2001)

by Grigoroudis, E., Politis, Y., Siskos, Y.
Published in International transactions in operational research (01.09.2002)