Coulomb-corrected propagation equation of femtosecond laser in field-ionized medium Cheng-Xin Yu, Shi-Bing Liu, Xiao-Fang Shu, Hai-Ying Song and Zhi Yang Eur. Phys. J. D, 67 4 (2013) 90 Published online: 30 April 2013 DOI: 10.1140/epjd/e2013-30658-8