BibTex format
@article{Liu:2016:10.1103/PhysRevD.93.043013,
author = {Liu, A and Pritchard, JR and Allison, R and Parsons, AR and Seljak, U and Sherwin, BD},
doi = {10.1103/PhysRevD.93.043013},
journal = {Physical Review D},
title = {Eliminating the optical depth nuisance from the CMB with 21 cm cosmology},
url = {http://dx.doi.org/10.1103/PhysRevD.93.043013},
volume = {93},
year = {2016}
}