Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
vat hanh » vat thanh, van hanh, va hanh
cam thuc » am thuc, nam thuc, cam thu
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
va danh » va dinh, va dan, va hanh
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
ve cam » ve cham, ve cac, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y nang x ho. hieu ve cam thuc ((((vat hanh) or (van thanh))) or (va danh)) dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang x ho. hieu ve cam thuc ((((vat hanh) OR (van thanh))) OR (va danh)) dai cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach y nang x ho. hieu ve cam thuc ((((vat hanh) or (van thanh))) or (va danh)) dai cua tre*.