Perhaps you should try some spelling variations:
nang dong » nang song, lang dong, nang luong
va triet » va thiet, va trien, ve triet
nang doc » nang luc
nang doi » nang noi, hang doi, nhung doi
sach ky » sac ky, sach y, sach ty
te sach » toc sach
cac toc » cac toi, cac nuoc, cac thoi
hieu va » lieu va, hieu qua
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
toc xa » tuc xa, toc ta, hoc xa

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky dang xa hoi. hieu va cac toc xa ((((nang doi) OR (nang dong))) or (nang doc)) va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky dang xa hoi. hieu va cac toc xa ((((nang doi) OR (nang dong))) OR (nang doc)) va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky dang xa hoi. hieu va cac toc xa ((((nang doi) OR (nang dong))) or (nang doc)) va triet".
• Adding a wildcard symbol may retrieve word variants: te sach ky dang xa hoi. hieu va cac toc xa ((((nang doi) OR (nang dong))) or (nang doc)) va triet*.