Perhaps you should try some spelling variations:
khanh thai » nhanh thai, khanh thanh, khanh thuan
van khanh » van thanh, van hanh, van anh
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
thai ca » thai cua, thai cao, thai va
xuc van » duc van, luc van, vuc van
cac xuc » cam xuc, cac nuoc, chat xuc
ca tren » cau tren, cu tren, la tren
sach ky » sac ky, sach y, sach ty
hieu ve » hieu van
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: tu sach ky nang ((o hoi) or (o hai)). ((hieu ve) OR (hieu va)) cac xuc van khanh thai ca tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((o hoi) OR (o hai)). ((hieu ve) OR (hieu va)) cac xuc van khanh thai ca tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((o hoi) or (o hai)). ((hieu ve) OR (hieu va)) cac xuc van khanh thai ca tren".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((o hoi) or (o hai)). ((hieu ve) OR (hieu va)) cac xuc van khanh thai ca tren*.