Gaya APA

Sisteberio, M, P. et al (1997). ECOTOURISM . Laguna: Philippine coucil for agriculture, forestry and natural resources reseach and eelopment.

Gaya MLA

Sisteberio, Mercedita, P.. et al. "ECOTOURISM". Laguna: Philippine coucil for agriculture, forestry and natural resources reseach and eelopment, 1997. Text.