Found in articles
Fichier:Gerard Troost.jpg
DescriptionGerard Troost.jpg English: Gerard Troost (March 5, 1776–1850) Date Unknown date Source http://ihm.nlm.nih.gov/images/B24951 Author Unknown authorUnknown
Fichier:PSM V45 D158 Gerard Troost.jpg
DescriptionPSM V45 D158 Gerard Troost.jpg Gerard Troost Date 1894 Source Popular Science Monthly Volume 45 Author Unknown authorUnknown author Permission
Fichier:Notice of the Academy of Natural Sciences of Philadelphia - with an appendix (IA 0054000.nlm.nih.gov).pdf
whose
names appear to the minutes of this primary meeting, are Dr. Gerard
Troost, John Shinn, Jacob Gilliams, Nicholas Parmentier, John
Speakman, and
Fichier:Gerard Troost, State Geologist of Tennessee. From A critical summary of Troosts unpublished manuscript on the crinoids of Tennessee (1909) (20702930672).jpg
DescriptionGerard Troost, State Geologist of Tennessee. From A critical summary of Troosts unpublished manuscript on the crinoids of Tennessee (1909)
Fichier:Aert Schouman Pieter Tanje - Cornelis Troost Gerard Melderr.jpg
DescriptionAert Schouman Pieter Tanje - Cornelis Troost Gerard Melderr.jpg English: Cornelis Troost and Gerard Melderr Date 1751 Source Nieuw Schouburg on