Perhaps you should try some spelling variations:
pham duy » pham duc
van hanh » van thanh, ban hanh, van anh
phan duc » pham duc, phan tu, phan dau
te sach » toc sach
hai cua » thai cua, dai cua, hoi cua
va danh » va dinh, va dan, va hanh
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
y nang » ky nang, ly nang, v nang
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: te sach y nang ma hoi. hieu va ((phan duc) or (pham duy)) ((van hanh) or (va danh)) hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y nang ma hoi. hieu va ((phan duc) OR (pham duy)) ((van hanh) OR (va danh)) hai cua tre.
• Adding a wildcard symbol may retrieve word variants: te sach y nang ma hoi. hieu va ((phan duc) or (pham duy)) ((van hanh) or (va danh)) hai cua tre*.