Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
dinh vai » dinh van, dinh vi, dinh va
van dinh » van minh, van dich, va dinh
thuc van » thuc vat, thuc dan, thuc va
hieu va » lieu va, hieu qua
te sach » toc sach
son hai » cong hai
y nang » ky nang, ly nang, v nang
so hai » su hai, so ha, co hai
ro hai » co hai, o hai, do hai
vai su » va su, van su, lai su
va am » va lam, va cam

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

• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y nang ((ro hai) OR (((so hai) OR (son hai)))). hieu va am thuc van dinh vai su triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y nang ((ro hai) or (((so hai) OR (son hai)))). hieu va am thuc van dinh vai su triet~".
• Adding a wildcard symbol may retrieve word variants: te sach y nang ((ro hai) or (((so hai) OR (son hai)))). hieu va am thuc van dinh vai su triet*.