Perhaps you should try some spelling variations:
hieu luat » hieu qua
hieu luc » hieu qua
danh vai » danh sai, danh va, doanh van
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
va danh » va dinh, va dan, va hanh
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet

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 xa hoi. hieu ((hieu luc) OR (hieu luat)) nuoc va danh vai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang xa hoi. hieu ((hieu luc) OR (hieu luat)) nuoc va danh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang xa hoi. hieu ((hieu luc) OR (hieu luat)) nuoc va danh vai cua tre*.