@article{Bull2019,
author = {Bull, J.R. and Rowland, S.P. and Scherwitzl, E.B. and Scherwitzl, R. and Danielsson, K.G. and Harper, J.},
title= {Real-world menstrual cycle characteristics of more than 600,000 menstrual cycles},
year = {2019},
doi = {10.1038/s41746-019-0152-7},
volume = {2},
number = {1},
pages = {1--8},
}