Perhaps you should try some spelling variations:
sanh thien » sach thieu, hanh thiet, manh tien
thien bang » khien bang, thien ban, thien dang
cau theo » cau thi, cau tao
dua tren » dung tren
hieu van » hieu va, thien van, lieu va
va kinh » va tinh, qua kinh
so sanh » do sanh
van cau » van dau, van hau, van chat
bang va » hang va, ban va, trang va
va dinh » van dinh, va tinh, vu dinh
va hoi » xa hoi, va hoc, va hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sanh thien bang va hoi. hieu van cau truc ((va dinh) OR (va kinh)) vi ((dua tren) or (cau theo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sanh thien bang va hoi. hieu van cau truc ((va dinh) OR (va kinh)) vi ((dua tren) OR (cau theo)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sanh thien bang va hoi. hieu van cau truc ((va dinh) OR (va kinh)) vi ((dua tren) or (cau theo))".
• Adding a wildcard symbol may retrieve word variants: so sanh thien bang va hoi. hieu van cau truc ((va dinh) OR (va kinh)) vi ((dua tren) or (cau theo))*.