Hunter, D. R., Handcock, M. S., Butts, C. T., Goodreau, S. M. and Morris, M. (2008) “ergm: A Package to Fit, Simulate and Diagnose Exponential-Family Models for Networks”, Journal of Statistical Software, 24(3), pp. 1–29. doi: 10.18637/jss.v024.i03.