Jane Huffman Hayes Alex Dekhtyar Senthil Karthikeyan Sundaram Elizabeth Ashlee Holbrook Sravanthi Vadlamudi Alain April REquirements TRacing On target (RETRO): improving software maintenance through traceability recovery. 193-202 2007 3 ISSE 3 http://dx.doi.org/10.1007/s11334-007-0024-1 db/journals/isse/isse3.html#HayesDSHVA07