Perhaps you should try some spelling variations:
nang noi » nang doc
nang doi » nang doc, hang doi, nang dong
cac tuc » cac toc, cac tu, cac tac
sach ky » sac ky, sach y, sach kem
hieu ve » hieu va, hieu van
lang xa » lang ha, dang xay, lang van
sach ty » sach y, sach tu, sach thu
ve cac » va cac, vien cac
thiet » thieu

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 ve cac tuc xa ((nang doi) or (nang noi)) va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach ty)) lang xa hoi. hieu ve cac tuc xa ((nang doi) OR (nang noi)) va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sach ty)) lang xa hoi. hieu ve cac tuc xa ((nang doi) or (nang noi)) va thiet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sach ty)) lang xa hoi. hieu ve cac tuc xa ((nang doi) or (nang noi)) va thiet*.