Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam tu
ha thanh » va thanh, pham thanh, phan thanh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ky sang » ky nang, ky dang, ky tang
sang ma » tang ma, nang ma, sang tao
tai cua » thai cua, tai cuc, tri cua
ma hoi » mai hoi, xa hoi, ma hoa
cua te » cua tu

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 sang ma hoi. hieu van ((nam thuc) or (nam thu)) ha thanh tai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky sang ma hoi. hieu van ((nam thuc) OR (nam thu)) ha thanh tai cua te.
• Adding a wildcard symbol may retrieve word variants: tu sach ky sang ma hoi. hieu van ((nam thuc) or (nam thu)) ha thanh tai cua te*.