Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
co sach » bo sach, cuon sach, hoc sach
ve cham » va cham, vu cham, ve chim
ve chat » va chat, van chat
xa tinh » va tinh, ha tinh, ca tinh
tinh vi » trinh vi, tinh voi, tinh va
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) or (co sach)) ky nang x hoi. hieu ((ve cham) OR (ve chat)) tuc xa tinh vi cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (co sach)) ky nang x hoi. hieu ((ve cham) OR (ve chat)) tuc xa tinh vi cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (co sach)) ky nang x hoi. hieu ((ve cham) OR (ve chat)) tuc xa tinh vi cua vat".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (co sach)) ky nang x hoi. hieu ((ve cham) OR (ve chat)) tuc xa tinh vi cua vat*.