Perhaps you should try some spelling variations:
sach thue » sach thieu, sach tham, cach thuc
su triet » su viet, su tien, ve triet
sach thu » sach thieu, sach tham, cach thuc
van hang » van khang, van hoang, van thang
hang di » hang doi, hang vi, hang dien
tuc van » thuc van, truc van, tuc va
nang xa » nang x, lang xa, nang ma
va cam » va cham, va cac, va cao
ve cam » ve cham, ve cac, ve cai
di su » doi su, ki su, da su

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 thu) or (sach thue)) nang xa hoi. hieu ((ve cam) OR (va cam)) tuc van hang di su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach thu) OR (sach thue)) nang xa hoi. hieu ((ve cam) OR (va cam)) tuc van hang di su triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach thu) or (sach thue)) nang xa hoi. hieu ((ve cam) OR (va cam)) tuc van hang di su triet*".