Perhaps you should try some spelling variations:
va trien » va truyen, va thiet, va tuyen
nang doc » nang luc
nang doi » hang doi, nang dong, nhung doi
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
cac tuc » cac toc, cac tu, cac tac
hieu ve » hieu va, hieu van
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
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 doi) or (((nang noi) OR (nang doc)))) 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 doi) OR (((nang noi) OR (nang doc)))) va trien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky lang xa hoi. hieu ve cac tuc xa ((nang doi) or (((nang noi) OR (nang doc)))) va trien".
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang xa hoi. hieu ve cac tuc xa ((nang doi) or (((nang noi) OR (nang doc)))) va trien*.