Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
tay lang » tai lang, tay tang, tay quang
ve triet » va trien, su triet
vu hanh » vu khanh, vu thanh, du hanh
hanh ve » hanh vi, hanh va, hanh kem
ve cau » ke cau, va cau, le cau
ve cac » va cac, vien cac
ve ve » de ve, va ve, ke ve

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: hoc sach ((tay lang) OR (ky nang)) xa hoi. hieu ((ve cau) OR (ve cac)) phuc vu hanh ve ve triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ((tay lang) or (ky nang)) xa hoi. hieu ((ve cau) OR (ve cac)) phuc vu hanh ve ve triet~".
• Adding a wildcard symbol may retrieve word variants: hoc sach ((tay lang) or (ky nang)) xa hoi. hieu ((ve cau) OR (ve cac)) phuc vu hanh ve ve triet*.