Perhaps you should try some spelling variations:
pham duy » pham duc
tan hanh » tan thanh, tang hanh, toan hanh
sach thu » sach thue, sach thieu, sach tham
duy tan » duy tuan, duc tan, duy van
sach ty » sach y, sach tu, xach tay
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
ve pham » vi pham, v pham, ve phan
dai ve » dap ve, dau ve, dai de
dai va » mai va

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