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

Rich SM, Ferreira MU, Ayala FJ.  2000.  The origin of antigenic diversity in Plasmodium falciparum.. Parasitol Today. 16(9):390-6.

Rich SM, Ayala FJ.  2000.  Population structure and recent evolution of Plasmodium falciparum.. Proc Natl Acad Sci U S A. 97(13):6994-7001.

Ayala FJ, Escalante AA, Rich SM.  1999.  Evolution of Plasmodium and the recent origin of the world populations of Plasmodium falciparum.. Parassitologia. 41(1-3):55-68.

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.