Perhaps you should try some spelling variations:
van thinh » van thanh, van chinh, van minh
va trinh » van trinh, va tinh, lap trinh
cai nam » hai nam, mai nam, chi nam
cua tre » cua te, cuu tre, cua triet
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
ca nam » cua nam, ha nam, va nam
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky nang x ho. hieu ((ca nam) OR (cai nam)) qua ((va trinh) or (van thinh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky nang x ho. hieu ((ca nam) OR (cai nam)) qua ((va trinh) OR (van thinh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky nang x ho. hieu ((ca nam) OR (cai nam)) qua ((va trinh) or (van thinh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sac ky nang x ho. hieu ((ca nam) OR (cai nam)) qua ((va trinh) or (van thinh)) vi cua tre*.