1. Infrared Optical Constants of Ammonium Sulfate, Sahara Dust, Volcanic Pumice, and Flyash
2. Experiments Concerning Infrared Diffuse Reflectance Standards in the Range 08 to 200 Microns
3. Sulfur as a Standard of Reflectance in the Infrared
4. Egan, W.G.; Joseph, J., Jr. Infrared optical constants of sahara sand, volcanic ash, and water soluble aerosols. 18th Annual Review of the Conference on Atmospheric Transmission, Bedford, MA, 1995, pp.202-203.