Rabitsch, W.B. (1995): Metal accumulation in arthropods near a Lead/Zinc smelter in Arnoldstein, Austria. III. Arachnida. Environmental Pollution, 90: 249-257.
Rachel, G. (2004): The vertical distribution of ericoid, ecto, and arbuscular mycorrhizae in a mixed species forest soil: correlations with soil N and P distribution and affect on root topology. PhD. Thesis, The University of Georgia, Athens, Georgia, 129 pp.
Racoviţă, G. (1984): Ětude faunistique et écologique du milieu souterrain superficiel de la vallée d’ordîncuşa (Monts du Bihor). Trav. Inst. Spéol. „Emile Racovitza“, 23: 27-37.