Perry, J. (1989). A survey of slope condition on motorway earthworks in England and Wales. Transport and Road Research Laboratory.
Chicago-Zitierstil (17. Ausg.)Perry, J. A Survey of Slope Condition on Motorway Earthworks in England and Wales. Crowthorne: Transport and Road Research Laboratory, 1989.
MLA-Zitierstil (9. Ausg.)Perry, J. A Survey of Slope Condition on Motorway Earthworks in England and Wales. Transport and Road Research Laboratory, 1989.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.