Perhaps you should try some spelling variations:
lam truoc » lam thuoc, nam truoc, lam truong
truoc van » truc van, truong van, truoc bang
cua triet » cua viet, su triet, va triet
sach van » sach han, sach va, bach van
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
hanh de » hanh ve, hanh kem
cua tre » cua te, cuu tre, dua tren
ve lam » va lam, de lam, se lam
x hoi » xa hoi, o hoi, 5 hoi

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 van dong ((x hoi) OR (x ho)). hieu ve lam truoc van hanh de ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach van dong ((x hoi) OR (x ho)). hieu ve lam truoc van hanh de ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach van dong ((x hoi) OR (x ho)). hieu ve lam truoc van hanh de ((cua tre) or (cua triet))".
• Adding a wildcard symbol may retrieve word variants: su sach van dong ((x hoi) OR (x ho)). hieu ve lam truoc van hanh de ((cua tre) or (cua triet))*.