Perhaps you should try some spelling variations:
among learners » among farmers, among teachers, among learning
patients 2.2 » patients 3.1, patients _, patients 1
wang liang » wang yang
liang ying » liang liying, huang ying, zhang ying
2.2 among » 2.4.2 among, 2.15 among, 1.5 among
can lose » can close, can losers, can't lose
can lost » can cost, can post, can boost

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 ((wang liang) OR (liang ying)) ((can lose) OR (can lost)) patients 2.2 among learners ;~.
• Adding a wildcard symbol may retrieve word variants: wang ((wang liang) or (liang ying)) ((can lose) or (can lost)) patients 2.2 among learners ;*.