Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
su triet » su viet, su tien, ve triet
van hanh » ban hanh, van anh, van ban
cuu nong » cuu cong, cuu nang, cuu tong
cac truc » cau truc, cac tru, cac trung
su sach » so sach, vu sach
uu nang » cuu nang, vu nang, dun nang
qua cac » cua cac
doi su » oi su, don su, voi su
x hoi » xa hoi, o hoi, x ho

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 ((uu nang) or (cuu nong)) x hoi. hieu qua cac truc ((van hanh) OR (van thanh)) doi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((uu nang) OR (cuu nong)) x hoi. hieu qua cac truc ((van hanh) OR (van thanh)) doi su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((uu nang) or (cuu nong)) x hoi. hieu qua cac truc ((van hanh) OR (van thanh)) doi su triet".
• Adding a wildcard symbol may retrieve word variants: su sach ((uu nang) or (cuu nong)) x hoi. hieu qua cac truc ((van hanh) OR (van thanh)) doi su triet*.