Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
tinh lap » trinh lap, tinh lao, dinh lap
hang tai » hang va, dung tai
tai khoi » tai khoa, mai khoi, tao khoi
ve pham » vi pham, v pham, ve phan
va tinh » may tinh
hieu ve » hieu va, hieu van
ky hang » ky nang, ly hang, ky dang
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: ((te sach) or (toc sach)) ky hang tai khoi. hieu ve pham duc va tinh lap ((cua te) OR (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky hang tai khoi. hieu ve pham duc va tinh lap ((cua te) OR (cua tu))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ky hang tai khoi. hieu ve pham duc va tinh lap ((cua te) OR (cua tu))*".