Meson-baryon effective chiral Lagrangians at order $p^4$
  We construct the three-flavor Lorentz-invariant meson-baryon chiral Lagrangians at the order $p^4$, with which a full one-loop investigation may be performed. One obtains 540 independent terms. The processes with the minimal number of mesons and photons that this order Lagrangians may contribute to are also presented. 
Shao-Zhou Jiang, Qing-Sen Chen, Yan-Rui Liu
hep-ph