Perhaps you should try some spelling variations:
during crisis » during crises, housing crisis
2.1 debatten » 9.2 debatten, 3.2.6 debatten, die debatten
wang zhang » wang zheng, wang luhang, zhang zhang
zhang jing » zhang ming, zhang jin, zhang ping
2.1 debate » 11.1 debate, 2 debate, 3.4 debate
u.s senate » u.s state
how some » how women

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

• Performing a fuzzy search may retrieve terms with similar spellings: wang zhang jing ((((2.1 debate) OR (2.1 debatten))) or (u.s senate)) during crisis how some ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wang zhang jing ((((2.1 debate) OR (2.1 debatten))) OR (u.s senate)) during crisis how some ;.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wang zhang jing ((((2.1 debate) OR (2.1 debatten))) or (u.s senate)) during crisis how some ;".
• Adding a wildcard symbol may retrieve word variants: wang zhang jing ((((2.1 debate) OR (2.1 debatten))) or (u.s senate)) during crisis how some ;*.