HalvorsenO., and WisslerK. “Methods for Estimating the Density of Elaphostrongylus Rangiferi Mitskevich (Nematoda, Metastrongyloidea) Larvae in Faeces from Reindeer, Rangifer Tarandus L.”. Rangifer, Vol. 3, no. 1, May 1983, pp. 33-39, doi:10.7557/2.3.1.465.