Perhaps you should try some spelling variations:
cau theo » cau thi, cau tao
cau treo » cau tren, cau triet, cau trieu
van hanh » van thanh, ban hanh, van anh
tuc van » thuc van, truc van, tuc va
su sach » so sach, vu sach
tang xa » trang xa, tang ma, lang xa
sach 6 » sach y, sach 2
ve cam » ve cham, va cam, ve cai
ve cac » va cac, vien cac

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 6 tang xa hoi. hieu ((ve cam) or (ve cac)) tuc van hanh vi ((cau treo) OR (cau theo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach 6 tang xa hoi. hieu ((ve cam) OR (ve cac)) tuc van hanh vi ((cau treo) OR (cau theo)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach 6 tang xa hoi. hieu ((ve cam) or (ve cac)) tuc van hanh vi ((cau treo) OR (cau theo))".
• Adding a wildcard symbol may retrieve word variants: su sach 6 tang xa hoi. hieu ((ve cam) or (ve cac)) tuc van hanh vi ((cau treo) OR (cau theo))*.