Perhaps you should try some spelling variations:
thieu nghiem » thi nghiem, thu nghiem, thieu nhi
hoach thieu » sach thieu, hoc thieu, hoach chien
sach quan » sach quang, sach luan, tac quan
quan nghe » qua nghe, luan nghen, van nghe
nghe duoc » nghiem duoc, nghe nuoi, che duoc
duoc hoi » quoc hoi, duoc si, duc hoa
duoc hoc » quoc hoi
tu sach » thu sach, su sach, te sach
du hoc » tu hoc

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: (( tu sach quan nghe duoc hoi ) OR ( thu hoach thieu nghiem ((du hoc) OR (duoc hoc)) ))~.
• Adding a wildcard symbol may retrieve word variants: (( tu sach quan nghe duoc hoi ) or ( thu hoach thieu nghiem ((du hoc) or (duoc hoc)) ))*.