Perhaps you should try some spelling variations:
sach tham » sach nha
sach thu » sach thue, sach thieu, cach thuc
hieu van » hieu va, thien van, lieu va
hanh va » hang va, hanh vi
truc va » thuc va, thuc vat, trung va
nang xa » nang x, lang xa, nang ma
tuc va » thuc va, tuc xa, duc va
va cua » va chua, via cua, ca cua
cua te » cua tu

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: su ((sach thu) OR (sach tham)) nang xa hoi. hieu van nam ((tuc va) OR (truc va)) hanh va cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach thu) OR (sach tham)) nang xa hoi. hieu van nam ((tuc va) or (truc va)) hanh va cua te~".
• Adding a wildcard symbol may retrieve word variants: su ((sach thu) OR (sach tham)) nang xa hoi. hieu van nam ((tuc va) or (truc va)) hanh va cua te*.