1. An analysis of the requirements traceability problem;Gotel,1994
2. Trace queries for safety requirements in high assurance systems;Cleland-Huang,2012
3. Creating safety requirements traceability for assuring and recertifying legacy safety-critical systems;Hill,2010
4. Traceability fundamentals;Gotel,2012
5. How software engineers use documentation: the state of the practice;Lethbridge;IEEE Softw.,2003