Perhaps you should try some spelling variations:
khanh thai » nhanh thai, khanh thanh, khanh thuan
van khanh » van thanh, van hanh, van anh
dau tren » dau tien, dat tren, dau tieng
chat xuc » chat huu, cam xuc, chao xu
cau tren » cu tren, ca tren, cau treo
xuc van » duc van, luc van, vuc van
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
va chat » van chat, va phat, cao chat
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 va chat xuc van khanh thai ((cau tren) or (dau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((o hoi) OR (o hai)). hieu va chat xuc van khanh thai ((cau tren) OR (dau tren)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((o hoi) or (o hai)). hieu va chat xuc van khanh thai ((cau tren) or (dau tren))*.