Perhaps you should try some spelling variations:
thuat san » thuat toan, thuat song, thuat lanh
doanh van » doan van, doanh va, doanh ban
va doanh » van doanh, vay doanh, va danh
tu sach » thu sach, su sach, te sach
van cua » vang cua, ban cua, dan cua
cac xuc » cam xuc, cac nuoc, chat xuc
qua cac » cua cac
sang ma » tang ma, nang ma, sang tao
ky sang » ky nang, ky dang, ky tang
so sach » so sanh, bo sach, co sach
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa
xuc va » duc va, tuc va, luc va

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 (thuat san))) or (so sach)) ky sang ma hoi. hieu qua cac xuc va doanh van cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((tu sach) OR (thuat san))) OR (so sach)) ky sang ma hoi. hieu qua cac xuc va doanh van cua tre.
• Adding a wildcard symbol may retrieve word variants: ((((tu sach) or (thuat san))) or (so sach)) ky sang ma hoi. hieu qua cac xuc va doanh van cua tre*.