Perhaps you should try some spelling variations:
cau theo » cau thi, cau tao
thuc van » thuc vat, thuc dan, thuc va
tuc van » truc van, tuc va, duc van
su sach » so sach, vu sach
tang xa » trang xa, tang ma, lang xa
sach 7 » sach y, sach 2
ve cac » va cac, vien cac
ve cam » ve cham, va cam, ve cai
7 tang » 6 tang
vi cau » va cau, ve cau, di cau

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 7 tang xa hoi. hieu ((ve cam) or (ve cac)) ((tuc van) OR (thuc van)) hanh vi cau theo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach 7 tang xa hoi. hieu ((ve cam) OR (ve cac)) ((tuc van) OR (thuc van)) hanh vi cau theo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach 7 tang xa hoi. hieu ((ve cam) or (ve cac)) ((tuc van) OR (thuc van)) hanh vi cau theo".
• Adding a wildcard symbol may retrieve word variants: su sach 7 tang xa hoi. hieu ((ve cam) or (ve cac)) ((tuc van) OR (thuc van)) hanh vi cau theo*.