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
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
va hanh » va thanh, va danh, ban hanh
cam tuc » cam xuc, cam tu, nam thuc
van cam » van nam, van lam, van cau
nang xa » nang x, lang xa, nang ma
ca tren » cau tren, cu tren, la tren

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 thien nang xa hoi. hieu van cam tuc ((va hanh) OR (van hanh)) va ((cua tre) or (ca tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thien nang xa hoi. hieu van cam tuc ((va hanh) OR (van hanh)) va ((cua tre) OR (ca tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach thien nang xa hoi. hieu van cam tuc ((va hanh) OR (van hanh)) va ((cua tre) or (ca tren))".
• Adding a wildcard symbol may retrieve word variants: su sach thien nang xa hoi. hieu van cam tuc ((va hanh) OR (van hanh)) va ((cua tre) or (ca tren))*.