Perhaps you should try some spelling variations:
thuoc quyet » thuoc quyen, theo quyet, thuoc chuyen
dung thoi » dung thi, dung toi, dung thong
quen vang » quan van, que van, que lang
tac trung » trac trung, tai trung, tac trong
trung hoc » trung quoc
tac dung » sach dung, xay dung, tin dung
dung hoc » dong hoc, dung khoa, dung cho
hoc mo » hoc moi, hoc mot, hoc mon

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( dung thuoc quyet van. tac dung hoc mo ) or ( dung thoi quen vang. tac trung hoc mo ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( dung thuoc quyet van. tac dung hoc mo ) OR ( dung thoi quen vang. tac trung hoc mo )).
• Adding a wildcard symbol may retrieve word variants: (( dung thuoc quyet van. tac dung hoc mo ) or ( dung thoi quen vang. tac trung hoc mo ))*.