Forbes-Mckay, K. E.; Venneri, A. (2005). "Detecting subtle spontaneous language decline in early Alzheimer's disease with a picture description task". Neurological Sciences. 26 (4): 243–254. doi:10.1007/s10072-005-0467-9. PMID16193251. S2CID24475485. This reference discusses Butterworth's study on Reagan
Forbes-Mckay, K. E.; Venneri, A. (2005). "Detecting subtle spontaneous language decline in early Alzheimer's disease with a picture description task". Neurological Sciences. 26 (4): 243–254. doi:10.1007/s10072-005-0467-9. PMID16193251. S2CID24475485. This reference discusses Butterworth's study on Reagan
Forbes-Mckay, K. E.; Venneri, A. (2005). "Detecting subtle spontaneous language decline in early Alzheimer's disease with a picture description task". Neurological Sciences. 26 (4): 243–254. doi:10.1007/s10072-005-0467-9. PMID16193251. S2CID24475485. This reference discusses Butterworth's study on Reagan
ucl.ac.uk
Emeritus Staff – UCL Division of Psychology and Language Sciences, accessed 30 October 2012
ukwhoswho.com
BUTTERWORTH, Prof. Brian Lewis, Who's Who 2012, A & C Black, 2012; online edn, Oxford University Press, Dec 2011, accessed 30 October 2012