Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
ban thanh » ban hanh, ban hang
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
sach ky » sac ky, sach ty, sach kem
nang ma » tang ma, sang ma, mang may
nam cuc » nam cac, nam cua, nam thuc
cuc ban » cua ban, cac ban, cuu ban

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) OR (sach y)) ((nang ma) or (nang cao)) hoi. hieu van nam cuc ban thanh dai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach ky) OR (sach y)) ((nang ma) OR (nang cao)) hoi. hieu van nam cuc ban thanh dai cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((sach ky) OR (sach y)) ((nang ma) or (nang cao)) hoi. hieu van nam cuc ban thanh dai cua triet".
• Adding a wildcard symbol may retrieve word variants: toc ((sach ky) OR (sach y)) ((nang ma) or (nang cao)) hoi. hieu van nam cuc ban thanh dai cua triet*.