Perhaps you should try some spelling variations:
nam truoc » nam thuoc, lam truoc, nam truong
nang dai » nang dau, nang tai, lang dai
vinh cuu » dinh cuu, sinh cua, dinh cu
nam truc » nam thuc, nam trung, nam thuoc
tu sach » thu sach, su sach, te sach
va hanh » van hanh, va thanh, va danh
dai hai » dai han, dai hoi, dai tai
hieu va » lieu va, hieu qua
y nang » ky nang, ly nang, v nang
vi cuu » vi luu

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 y nang dai hai. hieu va ((nam truc) OR (nam truoc)) va hanh ((vi cuu) or (vinh cuu)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang dai hai. hieu va ((nam truc) OR (nam truoc)) va hanh ((vi cuu) OR (vinh cuu)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang dai hai. hieu va ((nam truc) OR (nam truoc)) va hanh ((vi cuu) or (vinh cuu)) tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang dai hai. hieu va ((nam truc) OR (nam truoc)) va hanh ((vi cuu) or (vinh cuu)) tre*.