Perhaps you should try some spelling variations:
thanh phan » thanh pho, thanh san, thanh toan
cau tren » cu tren, dau tren, ca tren
hieu van » hieu va, thien van, lieu va
cau treo » cau theo, cau triet, cau trieu
va thanh » gia thanh, ban thanh, va tinh
cham luc » cham soc, nhan luc, cham cuu
van cham » van chat, van tham, va cham
lang xa » lang ha, dang xay, lang van
sach ty » sach y, sach tu, sach thu
sac ky » cac ky, sai ky
luc va » duc va, tuc va, loc va

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) or (sach ty)) lang xa hoi. hieu van cham luc va thanh phan ((cau treo) OR (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sac ky) OR (sach ty)) lang xa hoi. hieu van cham luc va thanh phan ((cau treo) OR (cau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sac ky) or (sach ty)) lang xa hoi. hieu van cham luc va thanh phan ((cau treo) OR (cau tren))".
• Adding a wildcard symbol may retrieve word variants: tu ((sac ky) or (sach ty)) lang xa hoi. hieu van cham luc va thanh phan ((cau treo) OR (cau tren))*.