Perhaps you should try some spelling variations:
duc manh » suc manh, duc anh, duc minh
hang hai » hoang hai, hang tai, thanh hai
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
qua cac » cua cac
duc ban » duc tan, dua ban, duc man
duc van » duc va, duc tan, duc phan
hai cua » thai cua, dai cua, hoi cua
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: so sach ky nang xa hoi. hieu qua cac ((duc ban) or (((duc van) or (duc manh)))) hang hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang xa hoi. hieu qua cac ((duc ban) OR (((duc van) OR (duc manh)))) hang hai cua tre.
• Adding a wildcard symbol may retrieve word variants: so sach ky nang xa hoi. hieu qua cac ((duc ban) or (((duc van) or (duc manh)))) hang hai cua tre*.