Perhaps you should try some spelling variations:
hung cau » nhung cau, huong cau, hang cau
cua viet » ca viet, hoa viet, cua vat
cach tu » cach thuc
hieu va » lieu va, hieu qua
sach tu » sach thu, sach ty, sach uu
tuc va » thuc va, truc va, tuc xa
dan de » dan den, dang de, van de
de cua » le cua, te cua, dieu cua
va cam » va cham, va cac, va cao
ac va » tac va, bac va, mac va

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((sach tu) OR (cach tu)) hung cau hoi. hieu va cam ((ac va) or (tuc va)) dan de cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((sach tu) OR (cach tu)) hung cau hoi. hieu va cam ((ac va) OR (tuc va)) dan de cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((sach tu) OR (cach tu)) hung cau hoi. hieu va cam ((ac va) or (tuc va)) dan de cua viet".
• Adding a wildcard symbol may retrieve word variants: hoc ((sach tu) OR (cach tu)) hung cau hoi. hieu va cam ((ac va) or (tuc va)) dan de cua viet*.