Perhaps you should try some spelling variations:
hanh thai » nhanh thai, hinh thai, hanh tai
quoc ban » quoc bao, quoc lan, quoc quan
thai cua » than cua, tai cuc, tri cua
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
duc van » duc va, duc tan, duc manh
cuc ban » cua ban, cac ban, cuu ban
sach ky » sac ky, sach y, sach ty
van bao » van ban, van dao
tung ho » tuong ho, trung hoc, trung hoa
ky tung » ky tang, ky vung, ky thuong
cua tre » cua te, cuu tre, cua triet
ho hai » hoc hai, pho hai, cho hai

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 tung ho hai. hieu van bao ((((cuc ban) or (quoc ban))) or (duc van)) hanh thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky tung ho hai. hieu van bao ((((cuc ban) OR (quoc ban))) OR (duc van)) hanh thai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky tung ho hai. hieu van bao ((((cuc ban) or (quoc ban))) or (duc van)) hanh thai cua tre*.