Perhaps you should try some spelling variations:
dan thiet » luan thiet, toan thiet, doan thien
hanh voi » hanh vi, hanh noi, hanh moi
qua cham » qua hai, qua cac, va cham
cao hoi » cau hoi, co hoi, cao hoc
sach ty » sach tu, sach thu, xach tay
voi dan » hoi dan, voi can, doi dan
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa

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 ty) or (sach y)) nang cao hoi. hieu qua cham ((xuc va) OR (tuc va)) hanh voi dan thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach y)) nang cao hoi. hieu qua cham ((xuc va) OR (tuc va)) hanh voi dan thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ty) or (sach y)) nang cao hoi. hieu qua cham ((xuc va) OR (tuc va)) hanh voi dan thiet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sach y)) nang cao hoi. hieu qua cham ((xuc va) OR (tuc va)) hanh voi dan thiet*.