Perhaps you should try some spelling variations:
dinh dien » tinh dien, kinh dien, dich dien
dien cua » dieu cua, dien cuc, dien cu
so cham » so kham, co cham, so chat
hieu so » thieu so
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa
sach v » sach va, sach 2, sach vay
soc va » loc va, doc va, goc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach v) or (sach y)) nang ma hoi. hieu so cham ((soc va) OR (hoc va)) dinh dien cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach v) OR (sach y)) nang ma hoi. hieu so cham ((soc va) OR (hoc va)) dinh dien cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach v) or (sach y)) nang ma hoi. hieu so cham ((soc va) OR (hoc va)) dinh dien cua tre".
• Adding a wildcard symbol may retrieve word variants: te ((sach v) or (sach y)) nang ma hoi. hieu so cham ((soc va) OR (hoc va)) dinh dien cua tre*.