Perhaps you should try some spelling variations:
khanh thai » nhanh thai, khanh thanh, khanh thuan
van khanh » van thanh, van hanh, van anh
sach thu » sach thue, sach thieu, sach tham
thu hang » thi hang, thuc hanh, thu huong
thai cuu » thai cua, tai cuc, thi cuc
su sach » so sach, vu sach
cac xuc » cam xuc, cac nuoc, chat xuc
hieu ve » hieu va, hieu van
cuu tre » cua tre, cau tren, cau treo
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: su sach thu hang ((o hoi) or (o hai)). hieu ve ((cac xuc) or (hoc nuoc)) van khanh thai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thu hang ((o hoi) OR (o hai)). hieu ve ((cac xuc) OR (hoc nuoc)) van khanh thai cuu tre.
• Adding a wildcard symbol may retrieve word variants: su sach thu hang ((o hoi) or (o hai)). hieu ve ((cac xuc) or (hoc nuoc)) van khanh thai cuu tre*.