Perhaps you should try some spelling variations:
thanh kiem » thanh liem, khanh kiem, thanh kim
thien van » thi van
so sach » so sanh, bo sach, co sach
tuc gia » tac gia, duc gia, toc gia
cam tuc » cam xuc, cam tu, nam thuc
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
doc hai » hoc hai, duc hai, do hai
doc hoi » duoc hoi, hoc hoi, doi hoi
tra te » tra tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky nang ((doc hoi) OR (doc hai)). ((hieu va) or (thien van)) cam tuc gia thanh kiem tra te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang ((doc hoi) OR (doc hai)). ((hieu va) OR (thien van)) cam tuc gia thanh kiem tra te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky nang ((doc hoi) OR (doc hai)). ((hieu va) or (thien van)) cam tuc gia thanh kiem tra te".
• Adding a wildcard symbol may retrieve word variants: so sach ky nang ((doc hoi) OR (doc hai)). ((hieu va) or (thien van)) cam tuc gia thanh kiem tra te*.