First Stars. III. A detailed elemental abundance study of four extremely metal-poor giant stars
P. François, E. Depagne, V. Hill, M. Spite, F. Spite, B. Plez, T. C. Beers, B. Barbuy, R. Cayrel, J. Andersen, P. Bonifacio, P. Molaro, B. Nordström and F. Primas