Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
tu sach » thu sach, su sach, tu cach
duc ban » duc tan, duc van, duc man
vai cua » dai cua, hai cua, lai cua
dua ban » dia ban, cua ban, qua ban
hieu ve » hieu va, hieu van
nang ma » tang ma, sang ma, nang cao
te sach » toc sach
cua tre » cua te, cuu tre, cua triet
ve cam » ve cham, ve cac, va cam

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