Perhaps you should try some spelling variations:
cua viet » hoa viet, cua vat, cua dieu
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
hanh tai » thanh tai, hang tai, han tai
su sach » so sach, vu sach
ca viet » va viet, co viet, hoa viet
dua ban » dia ban, cua ban, qua ban
sach ky » sac ky, sach y, sach ty
duc man » duc manh, duc tan, duc mau
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky nang x hoi. hieu van cham ((duc man) or (dua ban)) hanh tai ((cua viet) OR (ca viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang x hoi. hieu van cham ((duc man) OR (dua ban)) hanh tai ((cua viet) OR (ca viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang x hoi. hieu van cham ((duc man) or (dua ban)) hanh tai ((cua viet) OR (ca viet))".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang x hoi. hieu van cham ((duc man) or (dua ban)) hanh tai ((cua viet) OR (ca viet))*.