Perhaps you should try some spelling variations:
thanh di » thanh doi, thanh de, thanh do
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
thuc va » thuc vat, thuc dan, thuc day
cuu tre » cua tre, cau tren, cau treo
ha hoi » hoa hoi, ha noi, xa hoi
y dang » ky dang, 2 dang, b dang
luc va » duc va, tuc va, loc va
_ dang » _ dan, 2 dang, _ danh
di cuu » di cau, di cua, dinh cuu

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 ((y dang) OR (_ dang)) ha hoi. hieu van nam ((luc va) or (thuc va)) thanh di cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((y dang) OR (_ dang)) ha hoi. hieu van nam ((luc va) OR (thuc va)) thanh di cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((y dang) OR (_ dang)) ha hoi. hieu van nam ((luc va) or (thuc va)) thanh di cuu tre".
• Adding a wildcard symbol may retrieve word variants: su sach ((y dang) OR (_ dang)) ha hoi. hieu van nam ((luc va) or (thuc va)) thanh di cuu tre*.