Perhaps you should try some spelling variations:
duc manh » suc manh, duc anh, duc minh
cua tre » cua te, cuu tre, cua triet
hoc can » hoc dan, hoc cac, hoc phan
dang ma » dang mau, dang mam, dang mat
hieu ve » hieu va, hieu van
ky dang » ky nang, ky danh
ve cac » va cac, vien cac
sac ky » cac ky, sai ky
ma hoi » mai hoi, xa hoi, ma hoa
vi cua » vai cua, di cua
te sac » te sach, te cac, te san

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sac ky dang ma hoi. hieu ve cac ((duc manh) or (((hoc can) or (hoc cao)))) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky dang ma hoi. hieu ve cac ((duc manh) OR (((hoc can) OR (hoc cao)))) hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: te sac ky dang ma hoi. hieu ve cac ((duc manh) or (((hoc can) or (hoc cao)))) hanh vi cua tre*.