Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
truc van » truc va, thuc van, truc ban
van hanh » van thanh, ban hanh, van anh
dat tren » dat trong, dua tren
sach ky » sac ky, sach y, sach ty
nang co » nang cao, nang doc, nang noi
hieu va » lieu va, hieu qua
hanh ve » hanh vi, hanh va, hanh kem
ca tren » cau tren, cu tren, la tren
co hoi » co hoc, co loi
va cau » van cau, va cac, 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: thu sach ky nang co hoi. hieu va cau truc van hanh ve ((ca tren) OR (dat tren))~.
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang co hoi. hieu va cau truc van hanh ve ((ca tren) or (dat tren))*.