Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
ban thanh » ban hanh, ban hang
thu sach » tu sach, thuat sach, thu hoach
nang mai » nang ma, nang tai, lang mai
thanh va » thanh van, hanh va, thanh ha
cham duc » pham duc, cham soc, pham duy
mai hoi » mai khoi, dai hoi, lai hoi
hieu va » hieu qua
duc ban » duc tan, duc van, dua ban
va cua » va chua, via cua, ca cua
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) OR (thuoc sach)) ky nang mai hoi. ((hieu va) or (lieu va)) cham duc ban thanh va cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thuoc sach)) ky nang mai hoi. ((hieu va) OR (lieu va)) cham duc ban thanh va cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) OR (thuoc sach)) ky nang mai hoi. ((hieu va) or (lieu va)) cham duc ban thanh va cua te".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) OR (thuoc sach)) ky nang mai hoi. ((hieu va) or (lieu va)) cham duc ban thanh va cua te*.