Perhaps you should try some spelling variations:
tan thanh » tran thanh, tang thanh, toan thanh
pham duy » pham duc
sach dao » lanh dao
sach duy » sach dung, sach duoc, sach dat
dat cuu » dat cua
duy tan » duy tuan, duc tan, duy van
hieu va » lieu va, hieu qua
va pham » van pham, va phat, va phap
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa

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 duy) or (sach dao)) nang ma hoi. hieu va pham duy tan thanh ((dat cuu) OR (dat cau)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach duy) OR (sach dao)) nang ma hoi. hieu va pham duy tan thanh ((dat cuu) OR (dat cau)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach duy) or (sach dao)) nang ma hoi. hieu va pham duy tan thanh ((dat cuu) OR (dat cau)) tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach duy) or (sach dao)) nang ma hoi. hieu va pham duy tan thanh ((dat cuu) OR (dat cau)) tre*.