Perhaps you should try some spelling variations:
under debate » gender debates, badger debate, der debatte
und debate » un debate, und debatten, aid debate
crises how » crisis how
liang tan » liang dan, liang sun, wing tan
how scale » how stable, how small, how space
wing yan » wang yan, wing ian, wing tan

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((wing yan) or (liang tan)) ding ((und debate) or (under debate)) during crises how scale ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((wing yan) OR (liang tan)) ding ((und debate) OR (under debate)) during crises how scale ;.
• Adding a wildcard symbol may retrieve word variants: ((wing yan) or (liang tan)) ding ((und debate) or (under debate)) during crises how scale ;*.