@inproceedings{bollobas2003directed,
author = {Bollobas, Bela and Borgs, Christian and Chayes, Jennifer and Riordan, Oliver},
title = {Directed Scale-Free Graphs},
booktitle = {Proceedings of the 14th Annual ACM-SIAM Symposium on Discrete Algorithms (SODA)},
year = {2003},
month = {January},
abstract = {We introduce a model for directed scale-free graphs that grow with preferential attachment depending in a natural way on the in- and out-degrees. We show that the resulting in- and out-degree distributions are power laws with different exponents, reproducing observed properties of the worldwide web. We also derive exponents for the distribution of in- (out-) degrees among vertices with fixed out- (in-) degree. We conclude by suggesting a corresponding model with hidden variables.},
url = {http://approjects.co.za/?big=en-us/research/publication/directed-scale-free-graphs/},
pages = {132-139},
edition = {Proceedings of the 14th Annual ACM-SIAM Symposium on Discrete Algorithms (SODA)},
}