Langley, Gill. Animal research is poor science (archiviato dall'url originale il 22 giugno 2011)., Peter Tatchell interviews Gill Langley of the Dr Hadwen Trust, accessed July 5, 2010. Langley argues that animal research is holding back medical progress at circa 07:16 minutes, and that some of the tests are outdated at circa 11:15 minutes.