History of Space Exploration: Chapter 1, Exercise 1 — Possible Solution
======================================================================

Tsiolkovsky | 1857 to 1935 | Russian Empire / USSR | rocket equation (his date 1897), multistage rockets, liquid propellants
Goddard     | 1882 to 1945 | United States          | first liquid-fuel launch, 16 March 1926; 214 patents
Oberth      | 1894 to 1989 | Austria-Hungary (born), held Hungarian, Romanian and German citizenship | 1923 book Die Rakete zu den Planetenraumen

NOTE
Oberth's nationality is not a single label in the source, so give all three.