Perhaps you should try some spelling variations:
manh tuan » anh tuan, manh toan, minh tuan
tuan hoi » tan hoi, quang hoi, tuan hoan
duc manh » suc manh, duc anh, duc minh
so sach » so sanh, bo sach, co sach
van dau » van dao, phan dau
hoi cua » hoi chuc
van cau » van hau, van chat, toan cau
tu nong » tu dong, tu cong, tu tong
tu nang » tru nang, tu nano, tu lang
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 ((tu nang) OR (tu nong)) xa hoi. hieu ((van cau) or (van dau)) duc manh tuan hoi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((tu nang) OR (tu nong)) xa hoi. hieu ((van cau) OR (van dau)) duc manh tuan hoi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ((tu nang) OR (tu nong)) xa hoi. hieu ((van cau) or (van dau)) duc manh tuan hoi cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach ((tu nang) OR (tu nong)) xa hoi. hieu ((van cau) or (van dau)) duc manh tuan hoi cua tre*.