Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, tu cach
te sach » toc sach
nang ma » tang ma, sang ma, nang cao
qua cao » qua cac, qua ca, qua cai
duc van » duc tan, duc manh, duc phan
anh dat » thanh dat, lanh dao, dinh dat
dat cua » dai cua, day cua, mat cua
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa

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

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