Perhaps you should try some spelling variations:
dao thanh » ban thanh, tro thanh, de thanh
cac nhan » ca nhan, cac nha, cam nhan
cam thuc » am thuc, nam thuc, cam thu
vu sach » vu bach, su sach, vu khach
cua tre » cua te, cua triet, dua tren
sach ky » sac ky, sach y, sach ty
cuu tre » cau tren, cau treo
va cam » va cham, va cac, va cao
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky nang x hoi. lieu va cam thuc ((dao thanh) or (cac nhan)) di ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang x hoi. lieu va cam thuc ((dao thanh) OR (cac nhan)) di ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang x hoi. lieu va cam thuc ((dao thanh) or (cac nhan)) di ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang x hoi. lieu va cam thuc ((dao thanh) or (cac nhan)) di ((cua tre) OR (cuu tre))*.