@book{180623,
	author = {Richart, F. E. and Hall, John R.},
	title = {Vibrations of soils and foundations},
	publisher = {Prentice-Hall},
	year = {[1970]},
	series = {Prentice-Hall international series in theoretical and applied mechanics},
	address = {Englewood Cliffs, N.J.,}
}