. . "1108488870"^^ . . "Rocket Astrophysical Observatories K-2, K-3 and K-4"@en . . . "Rocket astrophysical observatories K-2, K-3 and K-4 were launched in Soviet Union in the 1960s and early 1970s under the direction of Grigor Gurzadyan of Byurakan Observatory in Armenia, for the study of the Solar ultraviolet and X-ray emission."@en . . "10769845"^^ . "Rocket astrophysical observatories K-2, K-3 and K-4 were launched in Soviet Union in the 1960s and early 1970s under the direction of Grigor Gurzadyan of Byurakan Observatory in Armenia, for the study of the Solar ultraviolet and X-ray emission."@en . . . . . "2815"^^ . . . . . . . . . . . . . . . . .