Burke WD, Malik HS, Rich SM, Eickbush TH.  2002.  Ancient lineages of non-LTR retrotransposons in the primitive eukaryote, Giardia lamblia.. Mol Biol Evol. 19(5):619-30.

Rich SM, Sawyer SA, Barbour AG.  2001.  Antigen polymorphism in Borrelia hermsii, a clonal pathogenic bacterium.. Proc Natl Acad Sci U S A. 98(26):15038-43.

Ayala FJ, Rich SM.  2000.  Genetic variation and the recent worldwide expansion of Plasmodium falciparum.. Gene. 261(1):161-70.