Uniqueness of sources in certain 3-Dimensional Networks Ingrid Abendroth This paper will investigate pairs of resistor arrays of the same shape ad with the same boundary data, and will show that two such arrays have the same internal source configurations. For certain rectangular and cylindrical networks, source location is uniquely determined by boundary data. 1. Introduction 2. Proof of Uniqueness in a 3-D Rectangular Network one unit in width 3. Uniqueness in all 3-Dimensional Rectangular Networks 4. Proof of Uniqueness in Cylindrical Networks 5. Proof of Uniqueness in Cylindrical Networks 6. Proving the uniqueness of a Cylindrical Network: a different approach