2 literature references for Astragalus propinquus Schischkin:

Author: Gontscharov, N. & Borissova,A.
Year: 1946
Title:
Source: In:Flora URSS, Vol.12. Mosqua, Leningrad. (Rus)
Author: Komarov,V.L. (Ed.)
Year: 1946
Title:
Source: Flora of the USSR Vol.X!! (Engl.Translation '97)