Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
su triet » su viet, su tien, ve triet
hieu van » hieu va, thien van, lieu va
thanh ha » thanh hoa, thanh hai, nhanh ha
thu sach » thuat sach, thuoc sach, thu hoach
chat duc » chat xuc, chat doc, chet duoc
duc ban » duc tan, duc van, dua ban
tu sach » su sach, te sach, tu cach
hieu ve » hieu va
lang ha » long ha
ky lang » ky nang, ky dang, ky tang
ha hoi » hoa hoi, ha noi, xa hoi
ha su » hay su, hoa su, nha su

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 (thu sach)) ky lang ha hoi. ((hieu ve) or (hieu van)) chat duc ban thanh ha su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky lang ha hoi. ((hieu ve) OR (hieu van)) chat duc ban thanh ha su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ky lang ha hoi. ((hieu ve) or (hieu van)) chat duc ban thanh ha su triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) ky lang ha hoi. ((hieu ve) or (hieu van)) chat duc ban thanh ha su triet*.