Volume 89, number 3 (1998), in the research brief (Article no. PR974281) "Plasmodium vivax: rapid detection by polymerase chain reaction and restriction fragment length polymorphism of the key mutation in dihydrofolate reductase-thymidylate synthase gene associated with pyrimethamine Resistance," by rachida tahar, philippe eldin de pecoulas, andre mazabraud, and leonardo K. Basco, pages 343-346