Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
su sach » so sach
cam qua » cau qua, cac qua, nam qua
vai cua » dai cua, hai cua, lai cua
cay qua » cau qua, cac qua, cay lua
nang ma » tang ma, sang ma, nang cao
vu sach » vu bach, vu khach
cua tre » cua te, cuu tre, cua triet
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: ((su sach) or (vu sach)) ky nang ma hoi. hieu van ((cam qua) OR (cay qua)) ban thanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) ky nang ma hoi. hieu van ((cam qua) OR (cay qua)) ban thanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (vu sach)) ky nang ma hoi. hieu van ((cam qua) OR (cay qua)) ban thanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu sach)) ky nang ma hoi. hieu van ((cam qua) OR (cay qua)) ban thanh vai cua tre*.