Perhaps you should try some spelling variations:
thanh mau » hanh mau, thanh san, thanh hai
thanh mat » thanh dat, thanh mot, thanh san
toc sach » hoc sach, doc sach, thuoc sach
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
y nang » ky nang, ly nang, v nang
ve cac » va cac, vien cac
du va » dau va, tu va, su va

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

• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang ((ma hoa) OR (mai hoi)). hieu ve cac du va ((thanh mat) OR (thanh mau)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang ((ma hoa) or (mai hoi)). hieu ve cac du va ((thanh mat) OR (thanh mau)) cua tre~".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang ((ma hoa) or (mai hoi)). hieu ve cac du va ((thanh mat) OR (thanh mau)) cua tre*.