Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
hoc viet » hoc hien
va thanh » gia thanh, ban thanh, va tinh
mai hoi » mai khoi, dai hoi, lai hoi
hai hoc » thai hoc, hai huoc, dai hoc
qua cam » qua cham, qua cac, qua ca
tu sach » thu sach, su sach, te sach
y tang » ky tang, 6 tang, 5 tang
ma hoi » xa hoi, ma hoa, me hoi
xuc va » duc va, tuc va, luc va
7 tang » 6 tang

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 ((y tang) or (7 tang)) ((ma hoi) OR (mai hoi)). hieu qua cam xuc va thanh hai hoc viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y tang) OR (7 tang)) ((ma hoi) OR (mai hoi)). hieu qua cam xuc va thanh hai hoc viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y tang) or (7 tang)) ((ma hoi) OR (mai hoi)). hieu qua cam xuc va thanh hai hoc viet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((y tang) or (7 tang)) ((ma hoi) OR (mai hoi)). hieu qua cam xuc va thanh hai hoc viet*.