Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
thu sach » thuat sach, thuoc sach, thu hoach
va thanh » gia thanh, ban thanh, va tinh
hieu van » hieu va, thien van, lieu va
van tham » van thanh, van tuan, van chat
va hanh » van hanh, va danh, ban hanh
doi cua » dai cua, hoi cua, dong cua
tu sach » su sach, te sach, tu cach
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet

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 (thu sach)) ky nang xa hoi. hieu van tham thuc ((va hanh) or (va thanh)) doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky nang xa hoi. hieu van tham thuc ((va hanh) OR (va thanh)) doi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky nang xa hoi. hieu van tham thuc ((va hanh) or (va thanh)) doi cua tre*.