Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, nam thu, nam tu
thanh do » thanh de, thanh hoa, thanh loi
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
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: toc sach ty nang xa hoi. hieu van ((nam thuc) or (am thuc)) day ((thanh do) OR (thanh pho)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty nang xa hoi. hieu van ((nam thuc) OR (am thuc)) day ((thanh do) OR (thanh pho)) cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ty nang xa hoi. hieu van ((nam thuc) or (am thuc)) day ((thanh do) OR (thanh pho)) cua te".
• Adding a wildcard symbol may retrieve word variants: toc sach ty nang xa hoi. hieu van ((nam thuc) or (am thuc)) day ((thanh do) OR (thanh pho)) cua te*.