I12, I18, D81, K13
C93 Field Experiments,D12 Consumer Economics Empirical Analysis,Q53 Solid Waste • Recycling Q58
D12, D83, P16, Q11, Q13, Q18, Z18
D03, D12, D91, L94, Q41, C93
D12, G22, L81. C93
D12, Q48, Q41, H23
I12, I18, C93
I12; I18; D83; C93; D85
J13;J22;I24;I12;J12;J16
I13, I15, O18, I12, Q53