Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
su sach » so sach, vu sach
quan xa » quan ha, quan cua, quan tai
quan va » quan vi, quan ha, luan va
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
vi cua » vai cua, di cua
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: ((su sach) OR (thu sach)) lien ((quan xa) OR (quan va)) hoi. hieu va am thuc va hanh vi cua vat~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (thu sach)) lien ((quan xa) OR (quan va)) hoi. hieu va am thuc va hanh vi cua vat~".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (thu sach)) lien ((quan xa) OR (quan va)) hoi. hieu va am thuc va hanh vi cua vat*.