Perhaps you should try some spelling variations:
va trien » va truyen, va thiet, va tuyen
vien cac » vien bach, vien dai, vien da
va triet » va thiet, ve triet, cua triet
day hanh » day nhanh, day thanh, dao hanh
thuc day » thuc dan, thuc vat
sach ky » sac ky, sach y, sach ty
hanh de » hanh ve, hanh kem
su sach » so sach, vu sach
ve cam » ve cham, ve cac, va cam
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 ky nang x hoi. hieu ((ve cam) or (vien cac)) thuc day hanh de ((va triet) OR (va trien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang x hoi. hieu ((ve cam) OR (vien cac)) thuc day hanh de ((va triet) OR (va trien)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang x hoi. hieu ((ve cam) or (vien cac)) thuc day hanh de ((va triet) OR (va trien))".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang x hoi. hieu ((ve cam) or (vien cac)) thuc day hanh de ((va triet) OR (va trien))*.