Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
hanh dai » hanh tai, hanh dao, vanh dai
kho tang » cao tang
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
su sach » so sach, vu sach
ky tang » ky nang, ky dang, ky trong
ma hoi » mai hoi, xa hoi, ma hoa
ve cac » va cac, vien cac
dai va » mai va
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: su sach ((ky tang) OR (kho tang)) ma hoi. hieu ((ve cam) or (ve cac)) thuc va hanh dai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ky tang) OR (kho tang)) ma hoi. hieu ((ve cam) OR (ve cac)) thuc va hanh dai va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ky tang) OR (kho tang)) ma hoi. hieu ((ve cam) or (ve cac)) thuc va hanh dai va triet".
• Adding a wildcard symbol may retrieve word variants: su sach ((ky tang) OR (kho tang)) ma hoi. hieu ((ve cam) or (ve cac)) thuc va hanh dai va triet*.