Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
vu cham » va cham, vu kham, tu cham
cua tre » cua te, cuu tre, cua triet
dang ma » dang mau, dang mam, dang mat
ky dang » ky nang, ky danh
ma hoi » mai hoi, xa hoi, ma hoa
xuc va » duc va, tuc va, luc va
va cua » va chua, via cua, ca cua
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: ((te sach) or (toc sach)) ky dang ma hoi. hieu ((ve cam) or (vu cham)) xuc va hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky dang ma hoi. hieu ((ve cam) OR (vu cham)) xuc va hanh va cua tre.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ky dang ma hoi. hieu ((ve cam) or (vu cham)) xuc va hanh va cua tre*.