Perhaps you should try some spelling variations:
quan thanh » ban thanh, van thanh
thanh tai » thanh hai, thanh toan, doanh tai
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
cau treo » cau theo, cau tren, cau triet
sach ky » sac ky, sach y, sach ty
nam qua » nam quan, nam cua, nam mua
cuu tre » cua tre, cau tren
ma hoi » mai hoi, xa hoi, me hoi

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 nang ((ma hoi) or (ma hoa)). hieu van nam qua quan thanh tai ((cuu tre) or (cau treo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang ((ma hoi) OR (ma hoa)). hieu van nam qua quan thanh tai ((cuu tre) OR (cau treo)).
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang ((ma hoi) or (ma hoa)). hieu van nam qua quan thanh tai ((cuu tre) or (cau treo))*.