Perhaps you should try some spelling variations:
vai triet » va triet, va trien, ve triet
thu sach » thuat sach, thuoc sach, thu hoach
thi hanh » thi thanh
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
tu sach » su sach, te sach, tu cach
hanh xa » hanh ma, hanh xu, canh xa
ve cac » va cac, vien cac
va vai » va bai, va van, va dai
ve cam » ve cham, va cam, ve cai

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) OR (thu sach)) thi hanh xa hoi. hieu ((ve cam) or (ve cac)) thuc va hanh va vai triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) thi hanh xa hoi. hieu ((ve cam) OR (ve cac)) thuc va hanh va vai triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) thi hanh xa hoi. hieu ((ve cam) or (ve cac)) thuc va hanh va vai triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) thi hanh xa hoi. hieu ((ve cam) or (ve cac)) thuc va hanh va vai triet*.