Population difference study of few-cycle laser pulse propagating in near-resonant two-level atom mediumR.J. Zhang, D.Z. Yao, Q.Q. Xu and X.N. LiuEur. Phys. J. B, 84 2 (2011) 161-165DOI: https://doi.org/10.1140/epjb/e2011-20685-8