Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
hieu van » hieu va, thien van, lieu va
ban hang » ngan hang
hang tai » hang va, dung tai
dau tren » dau tien, dat tren, dau tieng
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
van cam » van nam, van lam, van cau
cam cac » ca cac, nam cac, cam chan
cac ban » cac dan, cac van, can ban
tai dau » tac dau, tai du, thi dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (thuat sach)) ky nang xa hoi. hieu van cam cac ban hang tai dau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (thuat sach)) ky nang xa hoi. hieu van cam cac ban hang tai dau tren.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (thuat sach)) ky nang xa hoi. hieu van cam cac ban hang tai dau tren*.