Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
dua tren » dung tren
sach ky » sach y, sach ty, sach kem
nang xa » nang x, lang xa, nang ma
van cau » van dau, van hau, van chat
va tich » va tinh, va dich
cu tren » tu tren
sac ky » cac ky, sai ky
cau tu » dau tu, cau truc

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach ky) or (sac ky)) nang xa hoi. hieu van cau tu va tich va ((cu tren) or (dua tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ky) OR (sac ky)) nang xa hoi. hieu van cau tu va tich va ((cu tren) OR (dua tren)).
• Adding a wildcard symbol may retrieve word variants: te ((sach ky) or (sac ky)) nang xa hoi. hieu van cau tu va tich va ((cu tren) or (dua tren))*.