The new hostilities between Sudan and South Sudan have generated renewed interest in two RVI publications: Douglas Johnson's When Boundaries Become Borders and Eddie Thomas' The Kafia Kingi Enclave. The books offer the most detailed available account of border communities in the Sudans, their shared resources and disputed boundaries. Meanwhile Douglas Johnson has published a follow-up note on Panthou/Heglig, site of the most recent conflict, outlining the historical background to the competing territorial claims from the governments of Sudan and South Sudan.