Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
duc ban » duc tan, duc van, dua ban
van cam » van nam, van lam, van cau
nang xa » lang xa, nang ma, mang xa
cam duc » cam xuc, cao duc, pham duc
cua tre » cua te, cuu tre, cua triet

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 y ((nang xa) OR (nang x)) hoi. hieu van cam duc ban ((thanh vai) or (thanh san)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y ((nang xa) OR (nang x)) hoi. hieu van cam duc ban ((thanh vai) OR (thanh san)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y ((nang xa) OR (nang x)) hoi. hieu van cam duc ban ((thanh vai) or (thanh san)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach y ((nang xa) OR (nang x)) hoi. hieu van cam duc ban ((thanh vai) or (thanh san)) cua tre*.