@article{articleaa32c537,
title   = {First stars: XIII. Two extremely metal-poor RR Lyrae stars},
author = {Hansen, C. J and Nordstrom, B and Bonifacio, P and Spite, M and Andersen, J and Beers, T C and Cayrel, R and Depagne, E and Molaro, P and Barbuy, Beatriz Leonor Silveira and Depagne, E and Francois, P and Hill, V and Plez, B and Sivarani, T},
year = {2011},
journal   = {Astronomy & Astrophysics}
}