Barker, D. J. (1991). An economic analysis of farming coffee and trees at Turrialba, Costa Rica: Comparing small farms with poro (Erythrina poeppigiana) only to those with both laurel (Cordia alliodora) and poro.
استشهاد بنمط شيكاغوBarker, David J. An Economic Analysis of Farming Coffee and Trees At Turrialba, Costa Rica: Comparing Small Farms With Poro (Erythrina Poeppigiana) Only to Those With Both Laurel (Cordia Alliodora) and Poro. 1991.
MLA استشهادBarker, David J. An Economic Analysis of Farming Coffee and Trees At Turrialba, Costa Rica: Comparing Small Farms With Poro (Erythrina Poeppigiana) Only to Those With Both Laurel (Cordia Alliodora) and Poro. 1991.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.