APA
Purwantra A, Pawirosoemardjo S, . (1991). Symptom development and spore dissemination of Corynespora leaf fall disease on Hevea rubber clone PPN 2058. : Menara Perkebunan.
Chicago
Purwantra A, Pawirosoemardjo S, . 1991. Symptom development and spore dissemination of Corynespora leaf fall disease on Hevea rubber clone PPN 2058. : Menara Perkebunan.
Harvard
Purwantra A, Pawirosoemardjo S, . (1991). Symptom development and spore dissemination of Corynespora leaf fall disease on Hevea rubber clone PPN 2058. : Menara Perkebunan.
MLA
Purwantra A, Pawirosoemardjo S, . Symptom development and spore dissemination of Corynespora leaf fall disease on Hevea rubber clone PPN 2058. : Menara Perkebunan. 1991.