Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
hanh tai » thanh tai, hang tai, han tai
va chat » van chat, va phat, cao chat
tai cua » thai cua, tai cuc, tri cua
vuc van » duc van, luc van, thuc van
xuc van » duc van, luc van, xuc ban
te sach » toc sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
hieu va » lieu va, hieu qua
o hai » co hai, so hai, o lai
o hoi » co hoi, o hoc, o hoa

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 ((o hoi) OR (o hai)). hieu va chat ((xuc van) or (vuc van)) hanh tai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty nang ((o hoi) OR (o hai)). hieu va chat ((xuc van) OR (vuc van)) hanh tai cua viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty nang ((o hoi) OR (o hai)). hieu va chat ((xuc van) or (vuc van)) hanh tai cua viet*".