Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
cham duc » pham duc, cham soc, pham duy
sach thu » sach thue, sach thieu, sach tham
tan vanh » tan vinh, tan thanh, tang hanh
tan van » tran van, tang van, luan van
sach tu » cach tu, sach ty, sach uu
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
va cham » va chat, va tham
dai su » dai sua, dai so, dan su

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 tu) or (sach thu)) nang xa hoi. hieu va cham duc ((tan vanh) OR (tan van)) dai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach tu) OR (sach thu)) nang xa hoi. hieu va cham duc ((tan vanh) OR (tan van)) dai su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach tu) or (sach thu)) nang xa hoi. hieu va cham duc ((tan vanh) OR (tan van)) dai su triet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach tu) or (sach thu)) nang xa hoi. hieu va cham duc ((tan vanh) OR (tan van)) dai su triet*.