Perhaps you should try some spelling variations:
qua cham » qua hai, qua cac, va cham
cham cac » cho cac, cham soc, cua cac
ban hanh » ban hang
hai cua » thai cua, dai cua, hoi cua
ban anh » ban banh, ban danh, bang anh
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
nang ma » tang ma, sang ma, nang cao
cua te » cua tu

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 ((nang x) or (nang ma)) hoi. hieu qua cham cac ((ban anh) OR (ban hanh)) hai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang x) OR (nang ma)) hoi. hieu qua cham cac ((ban anh) OR (ban hanh)) hai cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty ((nang x) or (nang ma)) hoi. hieu qua cham cac ((ban anh) OR (ban hanh)) hai cua te*".