Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
dau trong » dat trong, dao trong, dai trong
dau tren » dau tien, dau tieng, dua tren
dat tren » dat trong, dua tren
hieu ve » hieu va, hieu van
cac luc » cau luc, coc luc, cac nuoc
hanh ve » hanh vi, hanh va, hanh kem
nang co » nang cao, nang doc, nang noi
va hanh » van hanh, va thanh, va danh
ve cac » va cac, vien cac
luc va » duc va, tuc va, loc va
y nang » ky nang, ly nang, v nang
co hoi » co hoc, co loi

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 y nang co hoi. hieu ve cac luc va hanh ve ((((dau tren) OR (dau trong))) OR (dat tren))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach y nang co hoi. hieu ve cac luc va hanh ve ((((dau tren) OR (dau trong))) or (dat tren))~".
• Adding a wildcard symbol may retrieve word variants: thuoc sach y nang co hoi. hieu ve cac luc va hanh ve ((((dau tren) OR (dau trong))) or (dat tren))*.