Bicknell, D. J. (1975) Pica. A Childhood Symptom.
Bicknell, D. J., Clayton, B. E. & Delves, H. T. (1968) Lead in mentally retarded children. Journal of Mental Deficiency Research, 12, 282–293.
Bhalla, J. N., Khanna, P. K., Srivatsava, J. R., et al (1983) Serum zinc levels and pica. Indian Paediatrics, 20, 667–670.
Blundell, J. E. (1984) Serotonin and appetite. Neuropharmacology, 23, 1537–1551.
Bowen, D. M., Allen, S. J., Benton, J. S., et al (1983) Biochemical assessment of serotonergic and cholinergic dysfunction and cerebral atrophy in Alzheimer's disease. Journal of Neurochemistry, 41, 266–272.
Dickens, D. & Ford, R. N. (1942) Geophagy (dirt eating) among Mississippi negro children. American Sociology Review, 7, 59–65.
Emerson, E., Cummings, R., Barrett, S., et al (1988) Challenging behaviour and community services. Mental Handicap, 16, 16–19.
Kinnell, H. G. (1985) Pica as a feature of autism. British Journal of Psychiatry, 147, 80–82.
McLoughlin, I. J. (1987) The picas: a study of their aetiology, classification and the medical problems they cause. British Journal of Hospital Medicine, 37, 286–290.
McLoughlin, I. J. (1989) Pica as a cause of death in three mentally handicapped men. British Journal of Psychiatry, 152, 842–845.
Morris, C. H. & Fairburn, F. C. (1989) Eating habits in dementia: a descriptive study. British Journal of Psychiatry, 154, 801–806.
O'Brien, G. & Whitehouse, A. M. (1990) A study of deviant eating behaviour among mentally handicapped adults. British Journal of Psychiatry, 157, 281–284.
Sourander, P. & Sjogren, H. (1970) The concept of Alzheimer's disease and its clinical implications. In Alzheimer's Disease and Related Conditions (eds Wolstenholme, G. E. W. & O'Connor, M.). London: J&A Churchill.
Swift, W. J., Andrews, D. & Barklace, N. E. (1986) The relationship between affective disorder and eating disorders: a review of the literature. American Journal of Psychiatry, 143, 290–299.
Vermeer, D. E. & Frate, D. A. (1979) Geophagia in rural Mississippi: environmental and cultural contents and nutritional implications. American Journal of Clinical Nutrition, 32, 2129–2135.
Woody, R. H. (1971) Controlling pica via an environmental psychobehavioural strategy: with special reference to lead poisoning. Journal of School Health, 41, 548–555.
World Health Organization (1992) The ICD-10 Classification of Mental and Behavioural Disorders.