Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
dat tren » dat trong, dua tren
cay cong » cac cong, cao cong, cau cong
van hanh » ban hanh, van anh, van ban
cau xuc » cam xuc, cau luc, cau truc
su sach » vu sach
hieu va » lieu va, hieu qua
cong xa » cong xay, cong xua, cong ha
so sach » so sanh, bo sach, co sach
vi dat » voi dat, vi dai, va dat
va cau » van cau, va cac, va dau

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) OR (so sach)) cay cong xa hoi. hieu va cau xuc ((van hanh) or (van thanh)) vi dat tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) cay cong xa hoi. hieu va cau xuc ((van hanh) OR (van thanh)) vi dat tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (so sach)) cay cong xa hoi. hieu va cau xuc ((van hanh) or (van thanh)) vi dat tren".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (so sach)) cay cong xa hoi. hieu va cau xuc ((van hanh) or (van thanh)) vi dat tren*.