Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
kho tang » cao tang
cuu tre » cua tre, cau tren, cau treo
duc van » duc va, duc tan, duc manh
cam duc » cam xuc, cao duc, pham duc
hieu ve » hieu va
ky tang » ky nang, ky dang, ky trong
van hoc » van hoa
vi cuu » vi luu, vinh cuu
tu sac » tu sach, tu cac, tu san

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ((ky tang) OR (kho tang)) van hoc. ((hieu ve) or (hieu van)) cam duc van hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ((ky tang) OR (kho tang)) van hoc. ((hieu ve) OR (hieu van)) cam duc van hanh vi cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ((ky tang) OR (kho tang)) van hoc. ((hieu ve) or (hieu van)) cam duc van hanh vi cuu tre*".