DescriptionGerard Troost.jpg English: Gerard Troost (March 5, 1776–1850) Date Unknown date Source http://ihm.nlm.nih.gov/images/B24951 Author Unknown authorUnknown

DescriptionPSM V45 D158 Gerard Troost.jpg Gerard Troost Date 1894 Source Popular Science Monthly Volume 45 Author Unknown authorUnknown author Permission

whose names appear to the minutes of this primary meeting, are Dr. Gerard Troost, John Shinn, Jacob Gilliams, Nicholas Parmentier, John Speakman, and

DescriptionGerard Troost, State Geologist of Tennessee. From A critical summary of Troosts unpublished manuscript on the crinoids of Tennessee (1909)

DescriptionAert Schouman Pieter Tanje - Cornelis Troost Gerard Melderr.jpg English: Cornelis Troost and Gerard Melderr Date 1751 Source Nieuw Schouburg on