This is a list of the world's bus operating companies listed alphabetically by continent and country. This list includes companies both operating now and in the past.
... covered by US patents 3,726,146 (1973) and 5,353,655 (1994) by L.A. Mishler and US patent 5,800,311 (1998) by P.S.Chuang.
External links
www.gyrotwister.de ...