Perhaps you should try some spelling variations:
va trien » va truyen, va thiet, va tuyen
hang doi » hang di, hang loi, huong doi
nang doc » nang luc
hieu va » lieu va, hieu qua
cac tuc » cac toc, cac tu, cac tac
sach ky » sac ky, sach y, sach ty
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
tu sach » thu sach, su sach, te sach

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 va cac tuc xa ((((nang doc) or (hang doi))) 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 va cac tuc xa ((((nang doc) OR (hang doi))) OR (nang noi)) va trien.
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang xa hoi. hieu va cac tuc xa ((((nang doc) or (hang doi))) or (nang noi)) va trien*.