The Lancet, 374. www.thelancet.com/journals/lancet/article/PIIS0140-6736(09)61266-6/full… doi:10.1016/S0140-6736(08)61345-8
Talks about 6 months being a critical time; looks at what they are weaning onto now and what the impact is of rapid weaning.
Yoon PW, Black RE, Moulton LH, Becker S. Am J Epidemiol 1996. 143(11):1142-1148 The effects of not breastfeeding on mortality due to d...