Perhaps you should try some spelling variations:
sach day » sach dao, sach dat, sach dau
day nano » dan nano, day nang, day nhanh
nano cau » nang cau, bang cau, nano va
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
cua tre » cua te, cua triet, dua tren
hanh va » hang va, hanh vi
duc van » duc va, duc tan, duc manh
cuu tre » cau tren, cau treo
ve cac » vien cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach day nano cau hoi. hieu ((ve cac) or (va cac)) duc van hanh va ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach day nano cau hoi. hieu ((ve cac) OR (va cac)) duc van hanh va ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach day nano cau hoi. hieu ((ve cac) or (va cac)) duc van hanh va ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: su sach day nano cau hoi. hieu ((ve cac) or (va cac)) duc van hanh va ((cua tre) OR (cuu tre))*.