Petricek, Vaclav; Cox, Ingemar J.; Han, Hui; Councill, Isaac G.; Giles, C. Lee (2005). »A Comparison of On-Line Computer Science Citation Databases«. Research and Advanced Technology for Digital Libraries. LNCS. Springer-Verlag. 3652: 438–449. arXiv:cs/0703043. doi:10.1007/11551362_39. ISBN978-3-540-28767-4.
Petricek, Vaclav; Cox, Ingemar J.; Han, Hui; Councill, Isaac G.; Giles, C. Lee (2005). »A Comparison of On-Line Computer Science Citation Databases«. Research and Advanced Technology for Digital Libraries. LNCS. Springer-Verlag. 3652: 438–449. arXiv:cs/0703043. doi:10.1007/11551362_39. ISBN978-3-540-28767-4.