Perhaps you should try some spelling variations:
cac truc » cau truc, cac tru, cac trung
nang mai » nang ma, nang tai, lang mai
hieu va » lieu va, hieu qua
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
truc va » thuc va, thuc vat, trung va
su sach » so sach, vu sach
mai hoi » mai khoi, dai hoi, lai hoi
so sanh » do sanh
y nang » ky nang, ly nang, v nang
vi cua » di cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (so sanh)) y nang mai hoi. hieu va cac truc va hanh ((vi cua) or (vai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sanh)) y nang mai hoi. hieu va cac truc va hanh ((vi cua) OR (vai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sanh)) y nang mai hoi. hieu va cac truc va hanh ((vi cua) or (vai cua)) tre*.