Anton J M de Craen, Pieter J Roos, A Leonard de Vries, Jos Kleijnen
de Craen A J M, Roos P J, de Vries A L, Kleijnen J.
Effect of colour of drugs: systematic review of perceived effect of drugs and of their effectiveness
BMJ 1996; 313 :1624
doi:10.1136/bmj.313.7072.1624