Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
thanh dung » thanh duong, thanh tung, thanh hung
nang cong » nang song, dang cong, bang cong
cong tan » cong tac, cong san, cong thanh
tran tap » toan tap, tran tuan, trang tai
tran tan » tran tuan, tran van, tran thanh
va nang » van nang, da nang, cam nang

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: toc thieu sach - thanh dung va nang cong tan ((tran tap) OR (tran tan))~.
• Adding a wildcard symbol may retrieve word variants: toc thieu sach - thanh dung va nang cong tan ((tran tap) or (tran tan))*.