Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
dang thi » hoang thi, dang khoi
lang thi » lang thai, tang thi, lang phi
cac tac » cac toc, cac bac, cac dac
tac hoa » tap hoa, tac ha, lac hoa
sach ky » sac ky, sach y, sach kem
lang xa » lang ha, dang xay, lang van
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua

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 ky) or (sach ty)) lang xa hoi. hieu va cac tac hoa ((lang thi) OR (dang thi)) dau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach ty)) lang xa hoi. hieu va cac tac hoa ((lang thi) OR (dang thi)) dau tren*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sach ty)) lang xa hoi. hieu va cac tac hoa ((lang thi) OR (dang thi)) dau tren*".