Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
te sach » toc sach
ty nang » ty xang, ty hang, ly nang
van cac » van hac, van cau, van bac
vai cua » dai cua, hai cua, lai cua
co hai » co dai, co hoi, o hai
cac so » cac co, cac bo, cac ho
so van » su van, vo van
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: te sach ((ty nang) OR (ky nang)) co hai. hieu van cac so van hanh ((vi cua) or (vai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((ty nang) OR (ky nang)) co hai. hieu van cac so van hanh ((vi cua) OR (vai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((ty nang) OR (ky nang)) co hai. hieu van cac so van hanh ((vi cua) or (vai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: te sach ((ty nang) OR (ky nang)) co hai. hieu van cac so van hanh ((vi cua) or (vai cua)) tre*.