Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
hieu van » hieu va, thien van, lieu va
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
sach ty » sach y, sach tu, sach thu
van lam » van nam
lam duc » lam duoc, pham duc, nam duoc
duc van » duc va, duc tan, duc manh
hanh va » hanh vi
su sach » so sach, vu sach

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 ty ((nang ma) OR (tang ma)) hoi. hieu van lam duc van ((hanh va) OR (hang va)) cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty ((nang ma) OR (tang ma)) hoi. hieu van lam duc van ((hanh va) or (hang va)) cua viet~".
• Adding a wildcard symbol may retrieve word variants: su sach ty ((nang ma) OR (tang ma)) hoi. hieu van lam duc van ((hanh va) or (hang va)) cua viet*.