Suggested nomenclature for landslides - Cruden, D.M.; Novograd, S.; Pilot, G.A.; Krauter, E.; Bhandari, R.K.; Cotecchia, V.; Nakamura, H.; Okagbue, C.O.; Zhuoyuan, Zhang; Hutchinson, J.N.; Varnes, D.; Ter-Stepanian, G.I. (Bulletin of the International Association of Engineering Geology, 1990)