Pokorenie neba /
Gilʹberg, Lev Abramovich.
Erickson, John,1929-2002,former owner.StEdNL
Erickson, Ljubica,former owner.StEdNL
Moskva : Ordena "Znak pocheta", Izdatel'stvo DOSAAF SSSR,
1977.
John and Ljubica Erickson collection.