Perhaps you should try some spelling variations:
luc nganh » luc ngan, chuc nganh, luat nganh
cau tren » cu tren, dau tren, ca tren
hang dau » hang va, hang tai
sach ty » sach y, sach tu, sach thu
hang da » hang dam, hoang da, hang va
cau luc » cau truc, cau phuc
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
lang ha » long ha
mang xa » lang xa, mang may, dang xay
ve cau » ke cau, va cau, ve cac

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 ((mang xa) or (lang ha)) hoi. hieu ve cau luc nganh ((hang da) OR (hang dau)) cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((mang xa) OR (lang ha)) hoi. hieu ve cau luc nganh ((hang da) OR (hang dau)) cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty ((mang xa) or (lang ha)) hoi. hieu ve cau luc nganh ((hang da) OR (hang dau)) cau tren".
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((mang xa) or (lang ha)) hoi. hieu ve cau luc nganh ((hang da) OR (hang dau)) cau tren*.