Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
hanh ve » hanh va, hanh kem
cam hoc » cao hoc, am hoc, cam hoa
hieu va » lieu va, hieu qua
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
va cam » va cham, va cac, va cao
ke san » ke dan
te san » te ban, tu san, ta san

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te san) or (ke san)) ky tang xa hoi. hieu va cam hoc va ((hanh ve) OR (hanh vi)) cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te san) OR (ke san)) ky tang xa hoi. hieu va cam hoc va ((hanh ve) OR (hanh vi)) cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te san) or (ke san)) ky tang xa hoi. hieu va cam hoc va ((hanh ve) OR (hanh vi)) cau tren".
• Adding a wildcard symbol may retrieve word variants: ((te san) or (ke san)) ky tang xa hoi. hieu va cam hoc va ((hanh ve) OR (hanh vi)) cau tren*.