1. Antarctic Historic Sites. The Tourism Implications;J Hughes;Annals of Tourism Research,1994
2. Waste Disposal and the Wilderness in the Yukon Territory, Canada" (referring a survey of visitors in Yukon in 1992;J March;Cruise Tourism in the Canadian Arctic and its Implications" (referring a survey in 1993 an board Kapitan Klebnikov on a Northwest Passage journey)
3. Supplementum Epigraphicum GraecumKonya. Stela lap. calc. Op. cit. 49/50