@article{eage:/content/papers/10.3997/2214-4609.201407117, author = "Abraham, O. and Cötel, Ph. and Leonard, Ch. and Piwakowski, B. and Shahrour, I.", title = "Application of the "impact echo method" to the detection of underground cavities part II: field experiments", journal= "", year = "1998", volume = "", number = "", pages = "", doi = "https://doi.org/10.3997/2214-4609.201407117", url = "https://www.earthdoc.org/content/papers/10.3997/2214-4609.201407117", publisher = "European Association of Geoscientists & Engineers", issn = "2214-4609", type = "", eid = "cp-43-00092", }