Perhaps you should try some spelling variations:
phap duc » pham duc, phan duc, phap doc
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
hieu va » hieu qua
va danh » va dinh, va dan, va hanh
vai cua » dai cua, hai cua, lai cua
vi cua » di cua
x hoi » xa hoi, o hoi, x ho

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 ty nang x hoi. ((hieu va) or (lieu va)) phap duc va danh ((vi cua) OR (vai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang x hoi. ((hieu va) OR (lieu va)) phap duc va danh ((vi cua) OR (vai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang x hoi. ((hieu va) or (lieu va)) phap duc va danh ((vi cua) OR (vai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang x hoi. ((hieu va) or (lieu va)) phap duc va danh ((vi cua) OR (vai cua)) tre*.