Perhaps you should try some spelling variations:
sach loai » sach bai, cac loai, sach doi
van thanh » ban thanh, van tuan
cua viet » ca viet, hoa viet, cua vat
thai cua » than cua, tai cuc, tri cua
van nhan » van phan, danh nhan, van khanh
tu sach » thu sach, su sach, te sach
cao duc » dao duc, cao suc, giao duc
hieu va » lieu va, hieu qua
nang xa » lang xa, nang ma, mang xa
va cao » va cac, va co, va dao

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach loai ((nang xa) OR (nang x)) hoi. hieu va cao duc ((van nhan) or (van thanh)) thai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach loai ((nang xa) OR (nang x)) hoi. hieu va cao duc ((van nhan) OR (van thanh)) thai cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach loai ((nang xa) OR (nang x)) hoi. hieu va cao duc ((van nhan) or (van thanh)) thai cua viet".
• Adding a wildcard symbol may retrieve word variants: tu sach loai ((nang xa) OR (nang x)) hoi. hieu va cao duc ((van nhan) or (van thanh)) thai cua viet*.