Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
hanh te » hanh tu, hanh ve, hanh de
ly nang » ky nang, ly hang, ly vang
duc van » duc va, duc tan, duc manh
te cua » tue cua, le cua, de cua
ve cau » ke cau, va cau, ve cac
y nang » ky nang, v nang, may nang
cua tu » cua tuc, cua su, cua cu
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: toc sach ((y nang) OR (ly nang)) x hoi. hieu ((ve cau) OR (ket cau)) duc van hanh te cua tu~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((y nang) OR (ly nang)) x hoi. hieu ((ve cau) or (ket cau)) duc van hanh te cua tu~".
• Adding a wildcard symbol may retrieve word variants: toc sach ((y nang) OR (ly nang)) x hoi. hieu ((ve cau) or (ket cau)) duc van hanh te cua tu*.