Perhaps you should try some spelling variations:
danh doi » danh di, thanh doi, dung doi
tu sach » thu sach, su sach, te sach
van hai » van ha, van chat, van hanh
doi cua » dai cua, hoi cua
va danh » va dinh, va dan, va hanh
truc va » thuc va, thuc vat, trung va
van hac » van hoc, van ha, van chat
sach ky » sac ky, sach y, sach ty
van cac » van cau, van bac, dan cac
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
cua tre » cua te, cuu tre, cua triet

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 ky lang xa hoi. hieu ((van cac) or (((van hac) OR (van hai)))) truc va danh doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang xa hoi. hieu ((van cac) OR (((van hac) OR (van hai)))) truc va danh doi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky lang xa hoi. hieu ((van cac) or (((van hac) OR (van hai)))) truc va danh doi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang xa hoi. hieu ((van cac) or (((van hac) OR (van hai)))) truc va danh doi cua tre*.