Perhaps you should try some spelling variations:
manh hanh » xanh hanh, danh thanh, minh thanh
thu sach » tu sach, thuat sach, thuoc sach
hanh tai » thanh tai, hang tai, han tai
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
tu nong » tu dong, tu cong, tu tong
tu nang » tru nang, tu nano, tu lang
ve cac » va cac, vien cac
ve cai » va cai, ve tai, ve cau

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

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