@article{Salganik2004,
author = {Salganik, M.J. and Heckathorn, D.D.},
title= {Sampling and estimation in hidden populations using respondent-driven sampling},
year = {2004},
doi = {10.1111/j.0081-1750.2004.00152.x},
journal = {Sociological Methodology},
volume = {34},
number = {1},
pages = {193--239},
}