Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
nang toc » nang doc, nang hoc, nang thuc
toc hoc » toan hoc, duoc hoc
va chat » van chat, va phat, cao chat
sach ky » sac ky, sach y, sach ty
vu cham » va cham, vu kham, tu cham
va hanh » van hanh, va thanh, va danh
van cau » van dau, van hau, van chat
va cau » va cac, va dau, va cao

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

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