Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh oai
thanh tai » thanh hai, thanh toan, doanh tai
hieu van » hieu va, thien van, lieu va
cua tre » cua te, cua triet, dua tren
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cam qua » cau qua, cac qua, cay qua
van cam » van nam, van lam, van cau
nang ma » tang ma, sang ma, nang cao
cuu tre » cau tren, cau treo
ma hoi » mai hoi, xa hoi, ma hoa

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 nang ma hoi. hieu van cam qua quan ((thanh vai) or (thanh tai)) ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ma hoi. hieu van cam qua quan ((thanh vai) OR (thanh tai)) ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ma hoi. hieu van cam qua quan ((thanh vai) or (thanh tai)) ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ma hoi. hieu van cam qua quan ((thanh vai) or (thanh tai)) ((cua tre) OR (cuu tre))*.