Perhaps you should try some spelling variations:
sach thi » sach thu, sach tai, sach thieu
thi nang » thi cong, ki nang, thi hanh
nam truc » nam truoc, nam thuc, nam trung
truc ban » thuc ban, truc dan, truc van
hang tai » hang va, dung tai
ve triet » va trien, su triet
su sach » so sach, vu sach
cao hoi » cau hoi, co hoi, cao hoc
qua nam » quan nam, cua nam, quang nam
van tai » von tai, van tuan

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: su sach thi nang cao hoi. hieu qua nam truc ban ((hang tai) OR (van tai)) ve triet~.
• Adding a wildcard symbol may retrieve word variants: su sach thi nang cao hoi. hieu qua nam truc ban ((hang tai) or (van tai)) ve triet*.