Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dang xay » dang van, van xay
cam truc » cau truc, nam truc, lam truoc
truc may » tren may, truc va
sach ky » sac ky, sach y, sach ty
ky dang » ky nang, ky danh
xay hoi » xa hoi, tay hoi, cay phoi
hieu va » lieu va, hieu qua
ket van » viet van, ket doan, kien van
va cam » va cham, va cac, va cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky dang xay hoi. hieu va cam truc may tinh ((ket va) or (ket van)) trien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky dang xay hoi. hieu va cam truc may tinh ((ket va) OR (ket van)) trien.
• Adding a wildcard symbol may retrieve word variants: toc sach ky dang xay hoi. hieu va cam truc may tinh ((ket va) or (ket van)) trien*.