Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hieu quan » lieu quan, thien quan, lien quan
thu sach » thuat sach, thuoc sach, thu hoach
dang xay » dang van, van xay
danh vai » danh sai, danh va, doanh van
xay hoi » xa hoi, tay hoi, cay phoi
cau duc » cao duc, cau luc, chu duc
va danh » va dinh, va dan, va hanh
vai cua » dai cua, hai cua, lai cua
tu sach » su sach, te sach, tu cach
y dang » ky dang, 2 dang, _ dang

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (thu sach)) y dang xay hoi. ((hieu quan) or (hieu qua)) cau duc va danh vai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) y dang xay hoi. ((hieu quan) OR (hieu qua)) cau duc va danh vai cua triet.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) y dang xay hoi. ((hieu quan) or (hieu qua)) cau duc va danh vai cua triet*.