Perhaps you should try some spelling variations:
hoc sac » hoc sach, hoc cac, hoc mac
lai cua » dai cua, hai cua, lai chau
vai cua » dai cua, hai cua, bai cua
dang ma » dang mau, dang mam, dang mat
hieu ve » hieu va, hieu van
ky dang » ky nang, ky danh
ve cam » ve cham, ve cac, va cam
sac ky » cac ky, sai ky
loc va » hoc va, luc va
ma hoi » mai hoi, xa hoi, ma hoa

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

• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sac ky dang ma hoi. hieu ve cam ((duc va) OR (loc va)) thanh ((vai cua) OR (lai cua)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sac ky dang ma hoi. hieu ve cam ((duc va) or (loc va)) thanh ((vai cua) OR (lai cua)) tre~".
• Adding a wildcard symbol may retrieve word variants: hoc sac ky dang ma hoi. hieu ve cam ((duc va) or (loc va)) thanh ((vai cua) OR (lai cua)) tre*.