Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thi huu » thi hue, thi thuy
thi cuu » thi cuc, thi cu, thi cua
cao luc » bao luc, cao duc, cao suc
hieu va » lieu va, hieu qua
ky danh » ky anh
ky dang » ky nang
va cao » va cac, va co, va dao
luc va » duc va, tuc va, loc va
va dan » ca dan, va dao, va dau

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: thuoc sach ((ky dang) OR (ky danh)) xa hoi. hieu va cao luc va dan ((thi cuu) OR (thi huu)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ((ky dang) or (ky danh)) xa hoi. hieu va cao luc va dan ((thi cuu) OR (thi huu)) tre~".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ((ky dang) or (ky danh)) xa hoi. hieu va cao luc va dan ((thi cuu) OR (thi huu)) tre*.