Gordh J:r T. and Wiklund L. (1986) “A Method for Reliable and Simultaneous Cannulation of the Epidural and Subarachnoid Spaces in Pigs: A tool for the study of cerebrospinal fluid pharmacakinetics and drug penetration of the dura mater”, Upsala Journal of Medical Sciences, 91(1), pp. 111-115. doi: 10.3109/03009738609178497.