Perhaps you should try some spelling variations:
dau truc » cau truc, dai truc, doan truc
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » hieu qua
truc va » thuc va, thuc vat, trung va
va hanh » van hanh, va thanh, va danh
vi cu » vi su, vi du
vi xu » va xu, ve xu, vi su

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