Perhaps you should try some spelling variations:
cam truc » cau truc, nam truc, lam truoc
su sach » so sach, vu sach
dinh vi » dinh ve, dinh viet, dinh tri
va dinh » van dinh, va kinh, va tinh
truc va » thuc va, thuc vat, trung va
hieu va » hieu qua
cua tre » cua te, cuu tre, cua triet
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
so sanh » do sanh
vi cua » vai cua, di cua

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) or (so sanh)) ky lang xa hoi. ((hieu va) OR (lieu va)) cam truc va dinh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sanh)) ky lang xa hoi. ((hieu va) OR (lieu va)) cam truc va dinh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sanh)) ky lang xa hoi. ((hieu va) OR (lieu va)) cam truc va dinh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sanh)) ky lang xa hoi. ((hieu va) OR (lieu va)) cam truc va dinh vi cua tre*.