Debra Trusso Haley Bashar Nuseibeh Helen C. Sharp Josie Taylor The Conundrum of Categorising Requirements: Managing Requirements for Learning on the Move. 309-314 2004 conf/re/2004 RE https://doi.ieeecomputersociety.org/10.1109/RE.2004.49 db/conf/re/re2004.html#HaleyNST04