Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
ve triet » va trien, su triet
sach van » sach han, sach va, bach van
van hanh » van thanh, ban hanh, van anh
truc van » truc va, thuc van, truc ban
vien cac » vien bach, vien dai, vien da
van nang » van quang, van ban, van dong
nang xa » nang x, lang xa, nang ma
hanh di » hanh vi, hanh de, hang di
vu sach » vu bach, su sach, vu khach
ve cac » va cac

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

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