1. The Economic Significance of Tourism within the European Community,1983
2. see also 1st, 2nd, 3rd and 4th Reports of 1975, 1977, 1978 and 1981.
3. Tourism Policy and International Tourism in OECD Member Countries, 1972–1982;Organization for Economic Co-operation Development,1972
4. Tourism Past Present and Future;Burkart,1981
5. The Economic Significance of Tourism within the European Community,1983