@article{Kryukov:1970,author = {P. G. Kryukov and V. S. Letokhov},title = {Propagation of a Light pulse in a Resonantly amplifying (absorbing) medium},publisher = {Physics-Uspekhi},year = {1970},journal = {Phys. Usp.},volume = {12},number = {5},pages = {641-672},url = {https://ufn.ru/en/articles/1970/5/c/},doi = {10.1070/PU1970v012n05ABEH003957}}