Perhaps you should try some spelling variations:
dan dong » van dong, dan dung, dao dong
dan cong » dang cong, van cong, ban cong
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
cac tuc » cac toc, cac tu, cac tac
mang xa » lang xa, mang may, dang xay
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: su sach ky ((mang xa) or (nang x)) hoi. lieu va cac tuc va ((dan cong) OR (dan dong)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((mang xa) OR (nang x)) hoi. lieu va cac tuc va ((dan cong) OR (dan dong)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((mang xa) or (nang x)) hoi. lieu va cac tuc va ((dan cong) OR (dan dong)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((mang xa) or (nang x)) hoi. lieu va cac tuc va ((dan cong) OR (dan dong)) cua tre*.