Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
va chat » van chat, cao chat, hoa chat
nang ma » tang ma, sang ma, nang cao
ty nang » ky nang, ty xang, ty hang
ma hoi » mai hoi, xa hoi, ma hoa
di cua » dai cua, doi cua, de cua
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (toc sach)) ty nang ma hoi. hieu ((va chat) OR (va phat)) duc va hanh di cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ty nang ma hoi. hieu ((va chat) OR (va phat)) duc va hanh di cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ty nang ma hoi. hieu ((va chat) OR (va phat)) duc va hanh di cua te".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ty nang ma hoi. hieu ((va chat) OR (va phat)) duc va hanh di cua te*.