variation of ecological benefit
delay variation delay and delay variation bounded
interdecadal variation and interannual variation
noncyclic variation (=non-periodic variation)
Seasonal variation of diurnal variation
wide-agriculture with ecological type
a view of ecological development
accessibility surface of ecological restoration model
accounting ecological civilization
Adaptability to the ecological environment
Advance in ecological economics research
agric-ecological environment
agricultural and ecological water-saving
agricultural development-ecological reaction
agricultural ecological condition
agricultural ecological environment
Agricultural ecological safety
agricultural ecological sections
agricultural ecological security