Feng X, Rich SM, Tzipori S, Widmer G.  2002.  Experimental evidence for genetic recombination in the opportunistic pathogen Cryptosporidium parvum.. Mol Biochem Parasitol. 119(1):55-62.

Okhuysen PC, Rich SM, Chappell CL, Grimes KA, Widmer G, Feng X, Tzipori S.  2002.  Infectivity of a Cryptosporidium parvum isolate of cervine origin for healthy adults and interferon-gamma knockout mice.. J Infect Dis. 185(9):1320-5.

Rich SM, Rosenthal BM, Telford SR, Spielman A, Hartl DL, Ayala FJ.  1997.  Heterogeneity of the internal transcribed spacer (ITS-2) region within individual deer ticks.. Insect Mol Biol. 6(2):123-9.

Armstrong PM, Rich SM, Smith RD, Hartl DL, Spielman A, Telford SR.  1996.  A new Borrelia infecting Lone Star ticks.. Lancet. 347(8993):67-8.