Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
dang xay » dang van, van xay
thu sach » tu sach, thuat sach, thuoc sach
danh xay » manh xay, anh xay, dan xay
hieu van » hieu va, thien van, lieu va
sach ky » sac ky, sach y, sach ty
nam cuc » nam cac, nam cua, nam thuc
cuc ban » cua ban, cac ban, cuu ban
ban anh » ban hanh, ban banh, ban danh
anh hoi » anh noi, anh hoc, anh khoa
cua tre » cua te, cuu tre, dua tren

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky ((danh xay) or (dang xay)) hoi. hieu van nam cuc ban anh hoi ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((danh xay) OR (dang xay)) hoi. hieu van nam cuc ban anh hoi ((cua tre) OR (cua triet)).
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((danh xay) or (dang xay)) hoi. hieu van nam cuc ban anh hoi ((cua tre) or (cua triet))*.