Perhaps you should try some spelling variations:
van cham » van chat, va cham, van pham
hanh lai » hanh lam, hanh tai, thanh lap
ban hanh » ban hang
van tham » van thanh, van tuan, van chat
duc ban » duc tan, duc van, dua ban
tu sach » thu sach, su sach, te sach
tu nang » tru nang, tu nong, tu nano
sach tu » sach thu, cach tu, sach ty
ca viet » va viet, co viet, hoa viet
lai ca » lai cua, lai cam, loai ca
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach tu nang ((x hoi) or (o hoi)). hieu ((van cham) or (van tham)) duc ban hanh lai ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tu nang ((x hoi) OR (o hoi)). hieu ((van cham) OR (van tham)) duc ban hanh lai ca viet.
• Adding a wildcard symbol may retrieve word variants: tu sach tu nang ((x hoi) or (o hoi)). hieu ((van cham) or (van tham)) duc ban hanh lai ca viet*.