Perhaps you should try some spelling variations:
hac truc » hoc truc, hang truc, sach truc
vinh cuu » dinh cuu, sinh cua, dinh cu
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
truc va » thuc va, thuc vat, trung va
va hanh » van hanh, va thanh, va danh
va hac » van hac, va khac, va cac
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) OR (su sach)) ky nang x ho. hieu va hac truc va hanh ((vi cuu) or (vinh cuu)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang x ho. hieu va hac truc va hanh ((vi cuu) OR (vinh cuu)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) ky nang x ho. hieu va hac truc va hanh ((vi cuu) or (vinh cuu)) tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) ky nang x ho. hieu va hac truc va hanh ((vi cuu) or (vinh cuu)) tre*.