D91, J16, C93, D63, O12, J22
C93, J54, O12, O13
Q41, D12, Q48, O13, C93
G52, Q14, Q12, O12
N57,O12,O13,Q12,Q16,Q18
D73, I38, O12, O22, O43
D12, O12, Q54
G34, M14, Q56
), O13 (Economic Development: Agriculture; Natural Resources; Energy; Environment), C93 (Field Experiments)
Q50, Q54, Q56, Q58, O13, O10