Perhaps you should try some spelling variations:
during crisis » during crises, housing crisis
code during » care during, code using, role during
huang jing » huang ting, huang ying, huang bin
wang liang » wang yang
wang jing » wang ning, wang yang, wang yong
land code » land cover
how slum » how slow, how sub, how sun

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: wang ((((huang jing) OR (wang jing))) OR (wang liang)) land code during crisis how slum ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wang ((((huang jing) OR (wang jing))) or (wang liang)) land code during crisis how slum ;~".
• Adding a wildcard symbol may retrieve word variants: wang ((((huang jing) OR (wang jing))) or (wang liang)) land code during crisis how slum ;*.