Skilling, FC Jr; Weaver, TA; Kato, KP; Ford, JG; Dussia, EM (2005). "Effects of two eye drop products on computer users with subjective ocular discomfort". Optometry. 76 (1). St. Louis, Mo.: 47–54. doi:10.1016/s1529-1839(05)70254-2. PMID15682562.
Skilling, FC Jr; Weaver, TA; Kato, KP; Ford, JG; Dussia, EM (2005). "Effects of two eye drop products on computer users with subjective ocular discomfort". Optometry. 76 (1). St. Louis, Mo.: 47–54. doi:10.1016/s1529-1839(05)70254-2. PMID15682562.