Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
truc gia » truc giac, tuc gia, thuc giai
su sach » so sach, vu sach
ky sang » ky dang, ky tang, duy sang
mai hoi » mai khoi, dai hoi, lai hoi
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
ve cac » vien cac

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 ((ky sang) or (ky nang)) mai hoi. hieu ((ve cac) OR (va cac)) truc gia thanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ky sang) OR (ky nang)) mai hoi. hieu ((ve cac) OR (va cac)) truc gia thanh vai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ky sang) or (ky nang)) mai hoi. hieu ((ve cac) OR (va cac)) truc gia thanh vai cua tre*".