Perhaps you should try some spelling variations:
manh hanh » xanh hanh, danh thanh, minh thanh
sach ty » sach y, sach tu, sach thu
hanh va » hang va, hanh vi
cua tre » cua te, cuu tre, cua triet
va cao » va cac, va co, va dao
va cua » va chua, via cua, ca cua
ve cao » ve bao, ve cac, ve co
x hoi » xa hoi, o hoi, x ho

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach ty) or (sach thieu)) nang x hoi. hieu ((ve cao) OR (va cao)) suc manh hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ty) OR (sach thieu)) nang x hoi. hieu ((ve cao) OR (va cao)) suc manh hanh va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ty) or (sach thieu)) nang x hoi. hieu ((ve cao) OR (va cao)) suc manh hanh va cua tre".
• Adding a wildcard symbol may retrieve word variants: te ((sach ty) or (sach thieu)) nang x hoi. hieu ((ve cao) OR (va cao)) suc manh hanh va cua tre*.