Please always cite ETMC's N_f=2 paper's:
Dynamical twisted mass fermions I, (Ph. Boucaud et al.)
Dynamical Twisted Mass Fermions II, (Ph. Boucaud et al.)

Quantity	Publication
F, l3, l4	Scaling and chiral extrapolation, P. Dimopoulos et.al.
F, l3, l4 , l6  (PFF)	Electromagnetic form factor, R. Frezzotti, V. Lubicz, S. Simula
F, l3, l4  (scal)	Electromagnetic form factor, R. Frezzotti, V. Lubicz, S. Simula