Nordin, M, G Elfström, and P Dahlquist. “Intra-Abdominal Pressure Measurements Using a Wireless Radio Pressure Pill and Two Wire Connected Pressure Transducers: A Comparison”. Journal of Rehabilitation Medicine 16, no. 4 (January 4, 1984): 139–146. Accessed February 14, 2025. https://medicaljournalssweden.se/jrm/article/view/41530.