Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
hieu ve » hieu va, hieu van
duc van » duc tan, duc manh, duc phan
cua tre » cua te, cuu tre, cua triet
y nang » ly nang, v nang, may nang
ma hoi » mai hoi, xa hoi, ma hoa
ve cao » va cao, ve bao, ve cac
anh ve » hanh ve, anh va, anh viet
ve cua » le cua, de cua, te cua

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

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