Perhaps you should try some spelling variations:
van quang » van quan, tran quang, van tuan
cua triet » cua viet, su triet, va triet
van nang » van ban, van dong, van dung
hieu van » hieu va, thien van, lieu va
nam truc » nam truoc, nam thuc, nam trung
truc van » truc va, thuc van, truc ban
van hanh » van thanh, ban hanh, van anh
so sach » so sanh, bo sach, co sach
hanh de » hanh ve, hanh kem
cua tre » cua te, cuu tre, dua tren

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ((van nang) or (van quang)) x ho. hieu van nam truc van hanh de ((cua tre) OR (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((van nang) OR (van quang)) x ho. hieu van nam truc van hanh de ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ((van nang) or (van quang)) x ho. hieu van nam truc van hanh de ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: so sach ((van nang) or (van quang)) x ho. hieu van nam truc van hanh de ((cua tre) OR (cua triet))*.