Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
doan van » doan va, hoang van, luan van
danh vai » danh sai, danh va, doanh van
tu sach » su sach, te sach, tu cach
cuu tre » cua tre, cau tren, cau treo
hieu ve » hieu va, hieu van
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
xuc va » duc va, tuc va, luc va
ve cam » ve cham, ve cac, va cam

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) OR (thu sach)) ky tang xa hoi. hieu ve cam xuc va ((danh vai) or (doan van)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky tang xa hoi. hieu ve cam xuc va ((danh vai) OR (doan van)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ky tang xa hoi. hieu ve cam xuc va ((danh vai) or (doan van)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) ky tang xa hoi. hieu ve cam xuc va ((danh vai) or (doan van)) cuu tre*.