Perhaps you should try some spelling variations:
thien van » thi van
van hanh » van thanh, ban hanh, van anh
cua tre » cua te, cuu tre, cua triet
vai cua » dai cua, hai cua, lai cua
va hanh » va thanh, va danh, ban hanh
cau loc » hau loc, cau hoc, cau luc
van cau » van dau, van hau, van chat
sang ma » tang ma, nang ma, sang tao
nang xa » nang x, lang xa, nang ma
sac ky » cac ky, sai ky
tu sac » tu sach, tu cac, tu san

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 xa) or (sang ma)) hoi. thien van cau loc ((va hanh) OR (van hanh)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky ((nang xa) OR (sang ma)) hoi. thien van cau loc ((va hanh) OR (van hanh)) vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky ((nang xa) or (sang ma)) hoi. thien van cau loc ((va hanh) OR (van hanh)) vai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sac ky ((nang xa) or (sang ma)) hoi. thien van cau loc ((va hanh) OR (van hanh)) vai cua tre*.