Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
vat thanh » dat thanh, gat thanh, tat thanh
cua triet » cua viet, su triet, va triet
cau thuc » cau truc, cuu thuc, can thuc
sach 6 » sach y
sach 2 » sach y
ma hoi » mai hoi, ma hoa, me hoi
va cau » van cau, va cac, va dau

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: tu ((sach 6) OR (sach 2)) tang ((ma hoi) OR (xa hoi)). lieu va cau thuc vat thanh dai cua triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach 6) or (sach 2)) tang ((ma hoi) OR (xa hoi)). lieu va cau thuc vat thanh dai cua triet~".
• Adding a wildcard symbol may retrieve word variants: tu ((sach 6) or (sach 2)) tang ((ma hoi) OR (xa hoi)). lieu va cau thuc vat thanh dai cua triet*.