the 6 note beginning of the theme in string part is same from:
Stravinsky, Rite of Spring, Games of the Rival Cities, 2nd Theme
theme starts coming in at the 12:00 min mark in below video, the strings play it at 12:16:
https://www.youtube.com/watch?v=4am3YRpfiHs I found this:
"Boosey & Hawkes, bought the rights to "Rite of Spring" from the composer in 1947."