Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
toc sach » hoc sach, doc sach, thuoc sach
cac truc » cau truc, cac tru, cac trung
truc van » truc va, thuc van, truc ban
dua tren » dung tren
sach tu » sach thu, cach tu, sach ty
tu nong » tu dong, tu cong, tu tong
nong xa » song xa, dong xa, nong va
hieu va » lieu va, hieu qua
van han » van hanh, van phan, van nhan
han tai » hang tai, nhan tai, van tai

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 tu nong xa hoi. hieu va cac truc van han tai ((dua tren) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach tu nong xa hoi. hieu va cac truc van han tai ((dua tren) OR (cua triet)).
• Adding a wildcard symbol may retrieve word variants: toc sach tu nong xa hoi. hieu va cac truc van han tai ((dua tren) or (cua triet))*.