Perhaps you should try some spelling variations:
nang doc » nang luc
va trien » va truyen, va thiet, va tuyen
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
cac tuc » cac toc, cac tu, cac tac
ve cac » va cac, vien 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 ky lang xa hoi. hieu ve cac tuc xa ((nang doc) or (nang noi)) va trien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang xa hoi. hieu ve cac tuc xa ((nang doc) OR (nang noi)) va trien.
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang xa hoi. hieu ve cac tuc xa ((nang doc) or (nang noi)) va trien*.