Perhaps you should try some spelling variations:
dang xay » dang van, van xay
thuc dan » thuc hanh, hoc dan, thuc vat
su sach » so sach, vu sach
danh va » doanh va, hanh va, anh va
thuc va » thuc vat, thuc day
va tham » van tham, va thanh, va thuat
va cham » va chat
xay hoi » xa hoi, tay hoi, cay phoi
cua tre » cua te, cuu tre, cua triet
sach o » sach lo, sac o, sach y
o dang » xo dang, do dang, so dang
va cua » va chua, via cua, ca cua

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 o dang xay hoi. hieu ((va cham) or (va tham)) ((thuc va) OR (thuc dan)) danh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach o dang xay hoi. hieu ((va cham) OR (va tham)) ((thuc va) OR (thuc dan)) danh va cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach o dang xay hoi. hieu ((va cham) or (va tham)) ((thuc va) OR (thuc dan)) danh va cua tre*".