@article{Ruggles2011,
author = {Ruggles, S. and Roberts, E. and Sarkar, S. and Sobek, M.},
title= {The North Atlantic Population Project: Progress and Prospects},
year = {2011},
doi = {10.1080/01615440.2010.515377},
journal = {Historical Methods},
volume = {44},
number = {1},
pages = {1--6},
}