Perhaps you should try some spelling variations:
van trinh » van thinh, van tinh, dan trinh
tu sach » thu sach, su sach, te sach
hieu ha » hieu hoa, hieu va, hieu ca
nam qua » nam quan, nam cua, nam mua
cua tre » cua te, cuu tre, cua triet
tu sac » tu cac, tu san, tu bac
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 sac) OR (tu sach)) ky nang x hoi. hieu ha nam qua ((lap trinh) or (van trinh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sac) OR (tu sach)) ky nang x hoi. hieu ha nam qua ((lap trinh) OR (van trinh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sac) OR (tu sach)) ky nang x hoi. hieu ha nam qua ((lap trinh) or (van trinh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sac) OR (tu sach)) ky nang x hoi. hieu ha nam qua ((lap trinh) or (van trinh)) vi cua tre*.