Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
van phan » van phong, van thanh, luan phan
thi hang » thi nang, thi hong, thi thanh
phan lap » phan dau
thi hanh » thi thanh
hieu ve » hieu va, hieu van
duc van » duc va, duc tan, duc manh
ve pham » vi pham, v pham, ve phan
cua tu » cua tuc, cua su, cua cu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach ((thi hang) or (thi hanh)) tao boi. hieu ve pham duc van phan lap ((cua te) or (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ((thi hang) OR (thi hanh)) tao boi. hieu ve pham duc van phan lap ((cua te) OR (cua tu)).
• Adding a wildcard symbol may retrieve word variants: doc sach ((thi hang) or (thi hanh)) tao boi. hieu ve pham duc van phan lap ((cua te) or (cua tu))*.