Bettycopa, A. (2015). Diversity and feeding guilds of understorey bird in an oil palm plantation and adjacent Peat Swamp forest in Betong Division, Sarawak, Malaysia. Universiti Malaysia Sarawak, (UNIMAS).
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Bettycopa, Amit. Diversity and Feeding Guilds of Understorey Bird in an Oil Palm Plantation and Adjacent Peat Swamp Forest in Betong Division, Sarawak, Malaysia. Universiti Malaysia Sarawak, (UNIMAS), 2015.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Bettycopa, Amit. Diversity and Feeding Guilds of Understorey Bird in an Oil Palm Plantation and Adjacent Peat Swamp Forest in Betong Division, Sarawak, Malaysia. Universiti Malaysia Sarawak, (UNIMAS), 2015.
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