Perhaps you should try some spelling variations:
thien van » thi van
nang doc » nang luc
dang van » hoang van, hang va
nang doi » nang noi, hang doi, nang dong
tu sach » thu sach, su sach, te sach
cac toc » cac toi, cac nuoc, cac thoi
sach ky » sac ky, sach y, sach ty
cac tuc » cac tu, cac tac, cac nuoc
ky dang » ky nang, ky danh

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 dang van hoa. thien van ((cac tuc) or (cac toc)) xa ((nang doi) OR (nang doc)) hoa viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky dang van hoa. thien van ((cac tuc) OR (cac toc)) xa ((nang doi) OR (nang doc)) hoa viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky dang van hoa. thien van ((cac tuc) or (cac toc)) xa ((nang doi) OR (nang doc)) hoa viet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky dang van hoa. thien van ((cac tuc) or (cac toc)) xa ((nang doi) OR (nang doc)) hoa viet*.