Perhaps you should try some spelling variations:
muong doong » muong duong, tuong duong, cuong duong
muong dong » muong duong, tuong dong, huong dong
hieu van » hieu va, thien van, lieu va
so sach » so sanh, bo sach, co sach
cam tuc » cam xuc, cam tu, nam thuc
sach ky » sac ky, sach y, sach ty
van cam » van nam, van lam, van cau
nang xa » lang xa, nang ma, mang xa
cua tre » cua te, cuu tre, cua triet
tuc mo » tuc mot, tuc co, duc mo

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky ((nang xa) OR (nang x)) hoi. hieu van cam tuc mo ((muong dong) or (muong doong)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky ((nang xa) OR (nang x)) hoi. hieu van cam tuc mo ((muong dong) OR (muong doong)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky ((nang xa) OR (nang x)) hoi. hieu van cam tuc mo ((muong dong) or (muong doong)) cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach ky ((nang xa) OR (nang x)) hoi. hieu van cam tuc mo ((muong dong) or (muong doong)) cua tre*.