First stars - XIII. Two extremely metal-poor RR Lyrae stars
C. J. Hansen, B. Nordström, P. Bonifacio, M. Spite, J. Andersen, T. C. Beers, R. Cayrel, F. Spite, P. Molaro, B. Barbuy, E. Depagne, P. François, V. Hill, B. Plez and T. Sivarani
A&A, 527 (2011) A65
DOI: https://doi.org/10.1051/0004-6361/201015076
