@article{Hamilton1964,
author = {Hamilton, W.D.},
title= {The genetical evolution of social behaviour (I and II)},
year = {1964},
doi = {10.1016/0022-5193(64)90038-4
10.1016/0022-5193(64)90039-6},
volume = {7},
number = {1},
pages = {1--52},
}