
1) City in Asia 2) City of Russia 3) City of Asia 4) City in Russia
Found on
https://www.crosswordclues.com/clue/borisoglebsk
[air base] For the airport in Kazan see Kazan Borisoglebskoye. Borisoglebsk (also Borisoglebsk East) is an air base in Voronezh Oblast, Russia located 6 km east of Borisoglebsk. It is a small military airfield. In October 1990 the 1080th Red Banner Aviation Centre for Retraining of Personnel named for V.P. Chkalov (1080 UATsPLS) was activat...
Found on
http://en.wikipedia.org/wiki/Borisoglebsk_(air_base)

city, Voronezh oblast (province), southwestern Russia, on the left bank of the Vorona River, near its confluence with the Khoper. Founded in 1646 as ...
Found on
http://www.britannica.com/eb/a-z/b/95
No exact match found.