Perhaps you should try some spelling variations:
vat hanh » vat thanh, van hanh, va hanh
su sach » so sach, vu sach
hieu ve » hieu van
hieu va » lieu va, hieu qua
hanh di » hanh vi, hanh de, hang di
cuu tre » cua tre, cau tren, cau treo
y nang » ky nang, ly nang, v nang
di cuu » di cau, di cua, dinh cuu
x hoi » xa hoi, o hoi, x ho
thuc » thu

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 hoi. ((hieu ve) OR (hieu va)) am thuc vat hanh di cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang x hoi. ((hieu ve) OR (hieu va)) am thuc vat hanh di cuu tre".
• Adding a wildcard symbol may retrieve word variants: su sach y nang x hoi. ((hieu ve) OR (hieu va)) am thuc vat hanh di cuu tre*.