Perhaps you should try some spelling variations:
su nhan » cu nhan, tu nhan, su nha
hieu su » hieu sau, tieu su, hieu so
nang ma » tang ma, sang ma, nang cao
sach v » sach va, sach 2, sach vay
luc va » duc va, tuc va
loc va » hoc va
dan vi » doan vi, don vi, dan va
vi cua » vai cua, di cua
cua tu » cua tuc, cua su, cua cu

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

• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach v) OR (sach y)) nang ma hoa. hieu su nhan ((luc va) OR (loc va)) dan vi cua tu~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach v) or (sach y)) nang ma hoa. hieu su nhan ((luc va) OR (loc va)) dan vi cua tu~".
• Adding a wildcard symbol may retrieve word variants: te ((sach v) or (sach y)) nang ma hoa. hieu su nhan ((luc va) OR (loc va)) dan vi cua tu*.