Perhaps you should try some spelling variations:
sach thien » sach thieu, sach tien, cach thien
thien nang » thien bang, thien dang, trien nang
hieu van » hieu va, thien van, lieu va
cau tren » cu tren, dau tren, ca tren
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
van cam » van nam, van lam, van cau
cam tuc » cam xuc, cam tu, nam thuc
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
cua tre » cua te, cuu tre, cua triet
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: tu sach thien nang xa hoi. hieu van cam tuc va hanh va ((cua tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thien nang xa hoi. hieu van cam tuc va hanh va ((cua tre) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: tu sach thien nang xa hoi. hieu van cam tuc va hanh va ((cua tre) or (cau tren))*.