Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
doanh van » doan van, doanh va, doanh ban
va doanh » van doanh, vay doanh, va danh
sang mai » sang ma, sang tai, lang mai
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
mai hoi » mai khoi, dai hoi, lai hoi
ky sang » ky nang, ky dang, ky tang
so sach » so sanh, bo sach, co sach
xuc va » duc va, tuc va, luc va
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: ((((tu sach) or (thuat sach))) or (so sach)) ky sang mai hoi. hieu qua cac xuc va doanh van cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((tu sach) OR (thuat sach))) OR (so sach)) ky sang mai hoi. hieu qua cac xuc va doanh van cua te.
• Adding a wildcard symbol may retrieve word variants: ((((tu sach) or (thuat sach))) or (so sach)) ky sang mai hoi. hieu qua cac xuc va doanh van cua te*.