Perhaps you should try some spelling variations:
may trinh » may tinh, lap trinh, quy trinh
vien cac » vien bach, vien dai, vien da
cua viet » hoa viet, cua vat, cua dieu
dang xay » dang van, van xay
trinh vi » trinh va, trinh ve, trinh viet
loc may » hoc may, loc mau, loai may
ca viet » va viet, co viet, hoa viet
xay hoi » xa hoi, tay hoi, cay phoi
ky dang » ky nang, ky danh
sac ky » cac ky, sai ky
ve cac » va cac
so sac » so sach, so dac

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

• If you are trying to use Boolean operators, they must be ALL CAPS: so sac ky dang xay hoi. hieu ((ve cac) OR (vien cac)) loc may trinh vi ((cua viet) OR (ca viet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sac ky dang xay hoi. hieu ((ve cac) OR (vien cac)) loc may trinh vi ((cua viet) or (ca viet))~".
• Adding a wildcard symbol may retrieve word variants: so sac ky dang xay hoi. hieu ((ve cac) OR (vien cac)) loc may trinh vi ((cua viet) or (ca viet))*.