Perhaps you should try some spelling variations:
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
qua dam » cua dam, qua da, dua dam
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
dam tu » nam tu, cam tu, tam tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ky) or (sach ty)) nang xa hoi. hieu qua dam tu va hanh vi ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach ty)) nang xa hoi. hieu qua dam tu va hanh vi ((cua tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sach ty)) nang xa hoi. hieu qua dam tu va hanh vi ((cua tre) or (cuu tre))*.