Perhaps you should try some spelling variations:
sach tham » sach nha
tham nang » nham nang, tham lang, tham nhung
cau treo » cau theo, cau tren, cau triet
hieu van » hieu va, thien van, lieu va
hanh di » hanh de, hang di, danh di
su sach » so sach, vu sach
cac duc » cao duc, cac dac, cac nuoc
nang xa » nang x, lang xa, nang ma

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 tham nang xa hoi. hieu van ((cac duc) or (cac du)) gia ((hanh di) OR (hanh vi)) cau treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tham nang xa hoi. hieu van ((cac duc) OR (cac du)) gia ((hanh di) OR (hanh vi)) cau treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach tham nang xa hoi. hieu van ((cac duc) or (cac du)) gia ((hanh di) OR (hanh vi)) cau treo".
• Adding a wildcard symbol may retrieve word variants: su sach tham nang xa hoi. hieu van ((cac duc) or (cac du)) gia ((hanh di) OR (hanh vi)) cau treo*.