Medicinal Plant Preparations Administered by Botswana Traditional Health Practitioners for Treatment of Worm Infections Show Anthelmintic Activities oleh Mthandazo Dube, Boingotlo Raphane, Bongani Sethebe, Nkaelang Seputhe, Tsholofelo Tiroyakgosi, Peter Imming, Cécile Häberli, Jennifer Keiser, Norbert Arnold, Kerstin Andrae-Marobela