We report results of the theoretical study of the dynamic properties of distributed Bragg reflector (DBR) lasers subject to an external optical feedback provided by a long-distance mirror. We adapt the Lang-Kobayashi (LK) model to the considered device. The adapted parameters Henry factor, photon life time, feedback strength, and modal group index entering the LK model depend strongly on the lasing wavelength of the solitary laser. The stationary states computed by the full and adapted LK models show good agreement. We consider the external reflectivity and phase and the solitary laser wavelength as a bifurcation parameters. Thus, we investigate the impact of these parameters on the stability of the stationary states.