TY - CPAPER KW - Invited AU - Francesco Sottile BT - Workshop on Common problems and solutions in core and valence theoretical spectroscopies, Paris (France) DA - 07/2017 PY - 2017 T2 - Workshop on Common problems and solutions in core and valence theoretical spectroscopies, Paris (France) TI - Introduction to Green functions methods for valence spectroscopies ER -