References ; ; ; & , 1998. Effect of Rainfall on Giardia and Crypto. Jour. AWWA, 90:9: 66. ; ; ; ; ; & , 2003. Improved Quantitative Estimates of Low Environmental Loading and Sporadic Periparturient Shedding of Cryptosporidiumparvum in Adult Beef Cattle. Appl. & Envir. Microbiol., 69:8: 4604. ; ; ; ; & , 2004. Seasonal Shedding of Multiple Cryptosporidium Genotypes in California Ground Squirrels (Spermophilus beecheyi). Appl. & Envir. Microbiol., 70:11: 6748. ; ; ; ; ; & , 1995.