Aleksander-Kwaterczak, U., and M. Gołas-Siarzewska. “Comparative Analysis of Helix Pomatia L. Shells Found in Soils With Varying Degrees of Contamination (southern Poland)”. Geology, Geophysics and Environment, vol. 41, no. 4, Mar. 2016, p. 299, doi:10.7494/geol.2015.41.4.299.