Perhaps you should try some spelling variations:
cua triet » cua viet, va triet
su triet » su viet, su tien, ve triet
thuc day » thuc dan, thuc vat
day hanh » day nhanh, day thanh, dao hanh
hanh di » hanh vi, hanh de, hang di
su sach » so sach, vu sach
va cam » va cham, va cac, va cao
ve cac » va cac, vien cac
y nang » ky nang, ly nang, v nang
x hoi » xa hoi, o hoi, x ho

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 y nang x hoi. hieu ((va cam) or (ve cac)) thuc day hanh di ((cua triet) OR (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang x hoi. hieu ((va cam) OR (ve cac)) thuc day hanh di ((cua triet) OR (su triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang x hoi. hieu ((va cam) or (ve cac)) thuc day hanh di ((cua triet) OR (su triet))".
• Adding a wildcard symbol may retrieve word variants: su sach y nang x hoi. hieu ((va cam) or (ve cac)) thuc day hanh di ((cua triet) OR (su triet))*.