Perhaps you should try some spelling variations:
nhanh thai » nhanh thi, nhanh thanh, nhanh thang
van nhanh » van thanh, van hanh, van khanh
cao tren » ca tren, cau tren, co tren
thai cao » tai cao, thoai cac, thuat cao
hieu van » hieu va, thien van, lieu va
duc van » duc va, duc tan, duc manh
van bac » van ban, van bao, van hac
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
co hai » co dai, co hoi, so hai
o hai » so hai, o lai, _ hai
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) or (co hai)))). hieu van bac duc van nhanh thai cao tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((o hoi) OR (((o hai) OR (co hai)))). hieu van bac duc van nhanh thai cao tren.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((o hoi) or (((o hai) or (co hai)))). hieu van bac duc van nhanh thai cao tren*.