Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
doc sach » hoc sach, toc sach, nuoc sach
van hanh » ban hanh, van anh, van ban
thi hang » thi hanh, thi nang, thi hong
hieu ve » hieu va, hieu van
ty hang » ly hang, ty xang, thu hang
cua tre » cua te, cuu tre, cua triet
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 hang) OR (thi hang)) xa hoi. hieu ve cam xuc ((van hanh) or (van thanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ((ty hang) OR (thi hang)) xa hoi. hieu ve cam xuc ((van hanh) OR (van thanh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach ((ty hang) OR (thi hang)) xa hoi. hieu ve cam xuc ((van hanh) or (van thanh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: doc sach ((ty hang) OR (thi hang)) xa hoi. hieu ve cam xuc ((van hanh) or (van thanh)) vi cua tre*.