Daniel M. Germán Massimiliano Di Penta Yann-Gaël Guéhéneuc Giuliano Antoniol Code siblings: Technical and legal implications of copying code between applications. 81-90 2009 MSR http://dx.doi.org/10.1109/MSR.2009.5069483 conf/msr/2009 db/conf/msr/msr2009.html#GermanPGA09