Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
sang tao » hang tai
tu sach » su sach, te sach, tu cach
vai cua » dai cua, hai cua, lai cua
dan vai » dan va, dan tai, dan vat
cac toc » cac toi, cac nuoc, cac thoi
hieu va » lieu va, hieu qua
hieu ve » hieu van
tao hoi » tao khoi, tao boi, tay hoi
ky sang » ky nang, ky dang, ky tang
toc va » hoc va, toc ta, tuc va
va dan » ca dan, va dao, va dau
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 (thu sach)) ky sang tao hoi. ((hieu ve) or (hieu va)) cac toc va dan vai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky sang tao hoi. ((hieu ve) OR (hieu va)) cac toc va dan vai cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ky sang tao hoi. ((hieu ve) or (hieu va)) cac toc va dan vai cua te*".