Perhaps you should try some spelling variations:
than thuc » thuan thuc, nhan thuc, toan thuc
tran van » luan van
doanh va » doan va, doanh tai, doanh cua
danh vai » danh sai, danh va, doanh van
su sach » so sach, vu sach
cuu tre » cau tren, cau treo
thuc va » thuc vat, thuc dan, thuc day
sach ta » sach tai, sach xa, sach ha
vi than » vi thanh, vi phan, va than
hieu vi » hieu voi, hieu va, hieu ve
van hoi » van hoa, van hoc, van hoe
ta tran » tan tran, ta trang, ha tran
cua tre » cua te, cua triet, 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: su sach ta tran van hoi. hieu vi than thuc va ((danh vai) or (doanh va)) ((cuu tre) or (cua tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ta tran van hoi. hieu vi than thuc va ((danh vai) OR (doanh va)) ((cuu tre) OR (cua tre)).
• Adding a wildcard symbol may retrieve word variants: su sach ta tran van hoi. hieu vi than thuc va ((danh vai) or (doanh va)) ((cuu tre) or (cua tre))*.