Hartvig , P., Gustafsson , L. L., Bergström , K., Moström , U., Pontén , U., Lindberg , B. and Lundqvist , H. (1987) “Positron Emission Tomography: An Animal Model of Spinal Distribution of Drugs after Intrathecal Administration”, Upsala Journal of Medical Sciences, 92(2), pp. 205-213. doi: 10.3109/03009738709178690.