Perhaps you should try some spelling variations:
sinh thai » dinh thi
hinh thai » tinh thai, dinh thi, chinh tai
cau treo » cau theo, cau tren, cau triet
thu san » thuy san, thu ban, phu san
hieu va » lieu va
nang xa » nang x, lang xa, nang ma
san ky » sang ky, van ky, dan ky
cac bo » bac bo, cac co
bo va » bao va, do va, so va

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu san ky nang xa hoi. ((hieu va) or (hieu qua)) cac bo va ((hinh thai) OR (sinh thai)) cau treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu san ky nang xa hoi. ((hieu va) OR (hieu qua)) cac bo va ((hinh thai) OR (sinh thai)) cau treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu san ky nang xa hoi. ((hieu va) or (hieu qua)) cac bo va ((hinh thai) OR (sinh thai)) cau treo".
• Adding a wildcard symbol may retrieve word variants: thu san ky nang xa hoi. ((hieu va) or (hieu qua)) cac bo va ((hinh thai) OR (sinh thai)) cau treo*.