Long-term magnetic activity of a sample of M-dwarf stars from the HARPS program - I. Comparison of activity indicesJ. Gomes da Silva, N. C. Santos, X. Bonfils, X. Delfosse, T. Forveille and S. UdryA&A, 534 (2011) A30DOI: https://doi.org/10.1051/0004-6361/201116971
