Gregor von Helmersen, Estonian-Russian geologist and engineer (b. 1803)
Gregor von Helmersen (11 October [O.S. 29 September] 1803 – 15 February [O.S. 3 February] 1885) was a Baltic German geologist.
Gregor von Helmersen, Estonian-Russian geologist and engineer (b. 1803)
Gregor von Helmersen (11 October [O.S. 29 September] 1803 – 15 February [O.S. 3 February] 1885) was a Baltic German geologist.