@article{Azose2019,
author = {Azose, J.J. and Raftery, A.E.},
title= {Estimation of emigration, return migration, and transit migration between all pairs of countries},
year = {2019},
doi = {10.1073/pnas.1722334116},
volume = {116},
number = {1},
pages = {116--122},
}