Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
ban hanh » ban hang
mai khoi » mai khoa, tai khoa, cac khoi
van hanh » van thanh, van anh, van ban
tai cuu » tai cuc, tai buu, tai cua
hieu ve » hieu va, hieu van
ky dang » ky nang, ky danh
ky lang » ky nang, ky tang, tay lang
cuu tre » cua tre, cau tren, cau treo
ve cam » ve cham, ve cac, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ((ky lang) or (ky dang)) mai khoi. hieu ve cam xuc ((van hanh) OR (ban hanh)) tai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ky lang) OR (ky dang)) mai khoi. hieu ve cam xuc ((van hanh) OR (ban hanh)) tai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((ky lang) or (ky dang)) mai khoi. hieu ve cam xuc ((van hanh) OR (ban hanh)) tai cuu tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ((ky lang) or (ky dang)) mai khoi. hieu ve cam xuc ((van hanh) OR (ban hanh)) tai cuu tre*.