O13; Q12; Q16; Z13; C93
C93, J16, O33, K42
(Consumer Economics: Empirical Analysis), Q42 (Alternative Energy Sources)
J24, O33, D91, J22
J24, O33
D22, D73, H25, H26, H32, O17, C93
I21, J24, O33, C93
D22, D25, D81, H23, H32, C90
O33; D83: O16; L14; O17; L81
M54, O33, J24, D23