Perhaps you should try some spelling variations:
dang thanh » dong thanh, dang hanh, hoang thanh
dau tieng » dau tien, cau tieng, day tieng
thu sach » thuat sach, thuoc sach, thu hoach
duc dang » duc dung, duc dong, duc bang
tu sach » su sach, te sach, tu cach
hieu va » lieu va, hieu qua
cam duc » cam xuc, cao duc, pham duc
san dau » van dau, san diu, ban dau
y nang » ly nang, v nang, may nang
va cam » va cham, va cac, va cao
x hoi » xa hoi, o hoi, x ho

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ((y nang) OR (ky nang)) x hoi. hieu va cam duc dang thanh san dau tieng~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ((y nang) or (ky nang)) x hoi. hieu va cam duc dang thanh san dau tieng~".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) ((y nang) or (ky nang)) x hoi. hieu va cam duc dang thanh san dau tieng*.