Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
cua tre » cua te, cuu tre, cua triet
va hanh » van hanh, va thanh, va danh
cac tuc » cac toc, cac tu, cac tac
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach tu, sach thu
sac ky » cac ky, sai ky
tuc va » thuc va, truc va, tuc xa

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

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