@article{DAN_1967_177_6_a20,
     author = {G. S. Ivanov-Kholodnyi},
     title = {Estimate of the negative ion concentration in the $D$~region of the ionosphere},
     journal = {Doklady Akademii Nauk},
     pages = {1328--1329},
     publisher = {mathdoc},
     volume = {177},
     number = {6},
     year = {1967},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1967_177_6_a20/}
}