First stars IX - Mixing in extremely metal-poor giants. Variation of the , [Na/Mg] and [Al/Mg] ratios
M. Spite, R. Cayrel, V. Hill, F. Spite, P. François, B. Plez, P. Bonifacio, P. Molaro, E. Depagne, J. Andersen, B. Barbuy, T. C. Beers, B. Nordström and F. Primas
, [Na/Mg] and [Al/Mg] ratios