Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
truc gia » truc giac, tuc gia, thuc giai
cam truc » cau truc, nam truc, lam truoc
tu sach » thu sach, su sach, te sach
vai cua » dai cua, hai cua, lai cua
hieu ve » hieu va, hieu van
lai hoi » dai hoi, lai hoa, lai roi
mai hoi » mai khoi, dai hoi, mai doi
ky sang » ky dang, ky tang, duy sang
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 ((ky sang) or (ky nang)) ((mai hoi) OR (lai hoi)). hieu ve cam truc gia thanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky sang) OR (ky nang)) ((mai hoi) OR (lai hoi)). hieu ve cam truc gia thanh vai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky sang) or (ky nang)) ((mai hoi) OR (lai hoi)). hieu ve cam truc gia thanh vai cua tre*".