Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
toc sach » hoc sach, doc sach, thuoc sach
vat hanh » vat thanh, van hanh, va hanh
hieu va » lieu va, hieu qua
va tham » van tham, va cham, va thanh
vai cua » dai cua, hai cua, lai cua
te ban » te bao
vi cua » di cua
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) or (te ban)) ky nang x hoi. hieu va tham thuc vat hanh ((vi cua) or (vai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (te ban)) ky nang x hoi. hieu va tham thuc vat hanh ((vi cua) OR (vai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (te ban)) ky nang x hoi. hieu va tham thuc vat hanh ((vi cua) or (vai cua)) tre*.