Great Panther Silver Reports Positive Preliminary Economic Assessment for the Coricancha Mine https://www.newswire.ca/news-releases/great-panther-silver-reports-positive-preliminary-economic-assessment-for-the-coricancha-mine-684145761.html Potential for Average Annual Production of Three Million Silver-Equivalent Ounces TSX: GPR NYSE AMERICAN: GPL VANCOUVER, May 31, 2018 /CNW/