Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
ban benh » san benh, ba benh, ban banh
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
van cau » van dau, van hau, van chat
cau duc » cao duc, cau luc, chu duc
duc ban » duc tan, duc van, dua ban
di cua » doi cua, de cua, do cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky nang xa hoi. hieu van cau duc ban benh ((di cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang xa hoi. hieu van cau duc ban benh ((di cua) OR (dai cua)) tre*.