Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
hanh va » hang va, hanh vi
thuc va » thuc vat, thuc dan, thuc day
sach ly » sach y, sach ty, sach hay
nang ma » tang ma, sang ma, nang cao
sach lo » sach dao, sach doi, sach hoi
ma hoi » mai hoi, xa hoi, ma hoa
luc va » duc va, tuc va, loc va
va cua » va chua, via cua, ca cua
cua te » cua tu

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 ly) or (sach lo)) nang ma hoi. hieu van nam ((luc va) or (thuc va)) hanh va cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ly) OR (sach lo)) nang ma hoi. hieu van nam ((luc va) OR (thuc va)) hanh va cua te.
• Adding a wildcard symbol may retrieve word variants: te ((sach ly) or (sach lo)) nang ma hoi. hieu van nam ((luc va) or (thuc va)) hanh va cua te*.