Institute of Transportation Studies University of California. Research Series - Institute of International Studies, University of California ; Institute of international studies Yale University Research series - Institute of International Studies, University of California, Berkeley ; Adolf D. May ; Institute of Transportation Studies University of California. insights from the university of California Research series - Institute of International Studies, University of California, Berkeley ; no. 35 Research series - Institute of International Studies, University of California, Berkeley ; no. 36 Working paper - Institute of Transportation Studies, University of California ; UCB-ITS-WP-79-8 Stanford Research Institute, University of California.