Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
minh via » minh va, minh vua, minh giao
hieu van » hieu va, thien van, lieu va
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
sach ty » sach y, sach tu, sach thu
cac lop » cac hop, cac loai
via cua » gia cua, gian cua, giau cua
cac co » cac cong
cua te » cua tu

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 ty ((nang xa) OR (nang ma)) hoi. hieu van ((cac lop) or (cac co)) van minh via cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ty ((nang xa) OR (nang ma)) hoi. hieu van ((cac lop) OR (cac co)) van minh via cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ty ((nang xa) OR (nang ma)) hoi. hieu van ((cac lop) or (cac co)) van minh via cua te".
• Adding a wildcard symbol may retrieve word variants: thu sach ty ((nang xa) OR (nang ma)) hoi. hieu van ((cac lop) or (cac co)) van minh via cua te*.