Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
hanh vai » hanh vi, hanh va, hanh tai
sach ky » sac ky, sach y, sach ty
vai cuu » vai cua
va hanh » van hanh, va thanh, va danh
cuu tre » cua tre, cau tren, cau treo
dang ma » dang mau, dang mam, dang mat
ky dang » ky nang, ky danh
ve cam » ve cham, ve cai, ve cau
ve cac » va cac, vien cac
va cam » va cham, va cac, va cao
xuc va » duc va, tuc va, luc va
ma hoi » mai hoi, xa hoi, ma hoa

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

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