Calvo, J., Quesada, C., Sánchez, A., González, P., Watson, V., & Bolaños, R. (1999). Forest cover in protected areas of Costa Rica between 1986/7 and 1996/7.
استشهاد بنمط شيكاغوCalvo, Julio, Carlos Quesada, Arturo Sánchez, Pablo González, Vicente Watson, و Rafael Bolaños. Forest Cover in Protected Areas of Costa Rica between 1986/7 and 1996/7. 1999.
MLA استشهادCalvo, Julio, et al. Forest Cover in Protected Areas of Costa Rica between 1986/7 and 1996/7. 1999.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.