Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, hieu ve
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
xa hanh » xa thanh, xa khanh, va hanh
tai cua » thai cua, tri cua, dai cua
cau tu » dau tu, cau truc
tu xa » tu xay, tu va, te xa

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 nang xa hoi. ((hieu van) or (lieu va)) cau tu xa hanh ((tai cua) OR (tai cuc)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. ((hieu van) OR (lieu va)) cau tu xa hanh ((tai cua) OR (tai cuc)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang xa hoi. ((hieu van) or (lieu va)) cau tu xa hanh ((tai cua) OR (tai cuc)) triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. ((hieu van) or (lieu va)) cau tu xa hanh ((tai cua) OR (tai cuc)) triet*.