Perhaps you should try some spelling variations:
vien cac » vien bach, vien dai, vien da
viec cac » viec cua, viec lam, viec va
va thanh » gia thanh, ban thanh, va tinh
doi cua » dai cua, hoi cua, dong cua
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
vi cua » vai cua, di cua
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: tu sach ty nang x hoi. hieu ((viec cac) OR (vien cac)) nuoc va thanh ((vi cua) or (doi cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang x hoi. hieu ((viec cac) OR (vien cac)) nuoc va thanh ((vi cua) OR (doi cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang x hoi. hieu ((viec cac) OR (vien cac)) nuoc va thanh ((vi cua) or (doi cua)) triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang x hoi. hieu ((viec cac) OR (vien cac)) nuoc va thanh ((vi cua) or (doi cua)) triet*.