Zack J. Butler Peter I. Corke Ronald A. Peterson Daniela Rus Dynamic Virtual Fences for Controlling Cows. 513-522 2004 ISER https://doi.org/10.1007/11552246_49 https://www.wikidata.org/entity/Q58626808 conf/iser/2004 db/conf/iser/iser2004.html#ButlerCPR04