BirdLife International (2008) Birds control insect pests in farmlands and forests. Presented as part of the BirdLife State of the world's birds website. Available from: http://www.birdlife.org/datazone/sowb/casestudy/99. Checked: 09/10/2014.
Rusch A, Valantin-Morison M, Sarthou JP, Roger-Estrade J. (2011) (på engelska). Multi-scale effects of landscape complexity and crop management on pollen beetle parasitism rate. Landscape Ecology.. doi:10.1007/s10980-011-9573-7.