Pham, M. T. N. “BOOK REVIEW: Halma, R. & Oplinger, C. S. (2001). The Lehigh Valley: A Natural and Environmental History. University Park, PA: The Pennsylvania State University Press. 361 Pages. ISBN: 0271020946.”. FIRE: Forum for International Research in Education, vol. 4, no. 1, Dec. 2018, doi:10.18275/fire201704011117.