Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
ban thanh » ban hanh, ban hang
thanh va » thanh van, hanh va, thanh ha
tu sach » thu sach, su sach, te sach
duc ban » duc tan, duc van, dua ban
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
va cua » va chua, via cua, ca cua
va cao » va co, va dao, va bao
cua te » cua tu

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