Perhaps you should try some spelling variations:
thanh thai » thanh hai, thanh tai, nhanh thai
van thanh » ban thanh, van tuan
cao tren » ca tren, cau tren, co tren
thai cao » tai cao, thoai cac, thuat cao
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
cac xuc » cam xuc, chat xuc, cac cuoc
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
mo hoc » mon hoc, co hoc
o hai » co hai, so hai, o lai

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 ((mo hoc) or (o hai)). hieu ve ((cac xuc) or (cac nuoc)) van thanh thai cao tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((mo hoc) OR (o hai)). hieu ve ((cac xuc) OR (cac nuoc)) van thanh thai cao tren.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((mo hoc) or (o hai)). hieu ve ((cac xuc) or (cac nuoc)) van thanh thai cao tren*.