Wu, J. T., & Barrett, R. K. (1993). Transportation facilities through difficult terrain: : proceedings of the conference on transportation facilities through difficult terrain. Rotterdam: A. A. Balkema.
Παραπομπή Chicago StyleWu, Jonathan T.H., and Robert K. Barrett. Transportation Facilities Through Difficult Terrain: : Proceedings of the Conference On Transportation Facilities Through Difficult Terrain. Rotterdam: A. A. Balkema, 1993.
Παραπομπή MLAWu, Jonathan T.H., and Robert K. Barrett. Transportation Facilities Through Difficult Terrain: : Proceedings of the Conference On Transportation Facilities Through Difficult Terrain. Rotterdam: A. A. Balkema, 1993.
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