Perhaps you should try some spelling variations:
thanh dat » thanh san, thanh hai, thanh van
thu sach » thuat sach, thuoc sach, thu hoach
hieu van » hieu va, thien van, lieu va
hanh tai » thanh tai, hang tai, han tai
pham cuc » pham chuc, pham duc, pham cua
van pham » san pham, van phan, van phat
nang ma » tang ma, sang ma, nang cao
cuc ban » cua ban, cac ban, cuu ban
tu sach » su sach, te sach, tu cach
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: ((thu sach) or (tu sach)) ky nang ma hoi. hieu van pham cuc ban ((thanh dat) or (hanh tai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (tu sach)) ky nang ma hoi. hieu van pham cuc ban ((thanh dat) OR (hanh tai)) cua tre.
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (tu sach)) ky nang ma hoi. hieu van pham cuc ban ((thanh dat) or (hanh tai)) cua tre*.