Perhaps you should try some spelling variations:
hieu cac » hieu luc, hieu va, hieu van
tu sach » thu sach, su sach, te sach
qua van » quan van, qua ban, qua san
sach ty » sach y, sach tu, sach thu
hieu xa » hiem xa, hieu va, hieu ca
ty nang » ky nang, ty xang, ty hang
cuu tre » cua tre, cau tren, cau treo
qua va » quan va, vua va, qua ca
vi cuu » vi luu, vinh cuu
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 xa) or (hieu cac)) nam ((qua va) or (qua van)) hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang x hoi. ((hieu xa) OR (hieu cac)) nam ((qua va) OR (qua van)) hanh vi cuu tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang x hoi. ((hieu xa) or (hieu cac)) nam ((qua va) or (qua van)) hanh vi cuu tre*.