Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
hau truc » hang truc, hoc truc, tu truc
van hang » van khang, van hoang, van thang
hang hai » hoang hai, hang tai, thanh hai
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky nang xa hoi. hieu van ((hau truc) or (cau truc)) van hang hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang xa hoi. hieu van ((hau truc) OR (cau truc)) van hang hai cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang xa hoi. hieu van ((hau truc) or (cau truc)) van hang hai cua tre*.