Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
tang ma » mang may, tang van
sang ma » nang ma, sang tao, mang may
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
ve cam » ve cham, ve cac, va cam
xuc va » duc va, tuc va, luc va
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky ((tang ma) or (sang ma)) hoi. hieu ve cam xuc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((tang ma) OR (sang ma)) hoi. hieu ve cam xuc va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((tang ma) or (sang ma)) hoi. hieu ve cam xuc va hanh vi cua tre*.