Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
hanh di » hanh vi, hanh de, hang di
su sach » so sach, vu sach
nang xa » lang xa, nang ma, mang xa
sach v » sach va, sach y, sach 2
ve cac » va cac, vien cac
ve cam » ve cham, va cam, ve cai
di va » dai va, di vao, doi va

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 v ((nang xa) or (nang x)) hoi. hieu ((ve cam) or (ve cac)) thuc van hanh di va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach v ((nang xa) OR (nang x)) hoi. hieu ((ve cam) OR (ve cac)) thuc van hanh di va triet.
• Adding a wildcard symbol may retrieve word variants: su sach v ((nang xa) or (nang x)) hoi. hieu ((ve cam) or (ve cac)) thuc van hanh di va triet*.