Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
vat thanh » dat thanh, gat thanh, tat thanh
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
cau treo » cau theo, cau tren, cau triet
tu cach » tu cac
su sach » so sach, vu sach
cuu tre » cua tre, cau tren
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: ((tu cach) or (su sach)) ky nang x hoi. hieu van nam thuc vat thanh vai ((cuu tre) OR (cau treo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cach) OR (su sach)) ky nang x hoi. hieu van nam thuc vat thanh vai ((cuu tre) OR (cau treo)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu cach) or (su sach)) ky nang x hoi. hieu van nam thuc vat thanh vai ((cuu tre) OR (cau treo))".
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (su sach)) ky nang x hoi. hieu van nam thuc vat thanh vai ((cuu tre) OR (cau treo))*.