Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
sach thu » sach thue, sach thieu, sach tham
sach ty » sach y, sach tu, xach tay
xuc van » duc van, luc van, xuc ban
hieu ve » hieu va, hieu van
hang ca » hang va, nang cao, hang tai
cua tre » cua te, cuu tre, cua triet
hang xa » hoang xa, hang va, lang xa
ve cam » ve cham, ve cac, va cam
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: doc ((sach ty) or (sach thu)) ((hang xa) OR (hang ca)) hoi. hieu ve cam xuc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((sach ty) OR (sach thu)) ((hang xa) OR (hang ca)) hoi. hieu ve cam xuc van hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((sach ty) or (sach thu)) ((hang xa) OR (hang ca)) hoi. hieu ve cam xuc van hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: doc ((sach ty) or (sach thu)) ((hang xa) OR (hang ca)) hoi. hieu ve cam xuc van hanh vi cua tre*.