Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
van hanh » van thanh, ban hanh, van anh
dau tren » dau tien, dat tren, dau tieng
ve cham » va cham, ve chat, vu cham
sach ky » sac ky, sach y, sach ty
va hanh » va thanh, va danh, ban hanh
nang co » nang cao, nang doc, nang noi
vu kham » vu khanh
ve dau » va dau, ve du, ke dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach ky nang co hoc. hieu ((ve cham) or (vu kham)) xuc ((va hanh) OR (van hanh)) ve dau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ky nang co hoc. hieu ((ve cham) OR (vu kham)) xuc ((va hanh) OR (van hanh)) ve dau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ky nang co hoc. hieu ((ve cham) or (vu kham)) xuc ((va hanh) OR (van hanh)) ve dau tren".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ky nang co hoc. hieu ((ve cham) or (vu kham)) xuc ((va hanh) OR (van hanh)) ve dau tren*.