Perhaps you should try some spelling variations:
dang tao » sang tao, nang tao, vang tao
thu sach » thuat sach, thuoc sach, thu hoach
cac thuc » cach thuc, cac thu, can thuc
tu sach » su sach, te sach, tu cach
hieu va » lieu va, hieu qua
vai cua » dai cua, hai cua, lai cua
dan vai » dan va, dan tai, dan vat
thuc va » thuc vat, thuc dan, thuc day
hieu ve » hieu van
tao hoi » tao khoi, tao boi, tay hoi
ky dang » ky nang, ky danh
va dan » ca dan, va dao, va dau
cua tu » cua tuc, cua su, cua cu

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 dang tao hoi. ((hieu ve) or (hieu va)) cac thuc va dan vai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky dang tao hoi. ((hieu ve) OR (hieu va)) cac thuc va dan vai cua tu*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ky dang tao hoi. ((hieu ve) or (hieu va)) cac thuc va dan vai cua tu*".