Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh day » hanh may, han day, hanh dao
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
day cua » dai cua
duc van » duc va, duc tan, duc manh
va pham » van pham, va phat, va phap
hieu va » lieu va, hieu qua
van hoe » van hoa, van hoc, van hieu
van hoi » van hoa, van hoc, van loi
ky dang » ky nang, ky danh
cua te » cua tu

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) or (toc sach)) ky dang ((van hoi) or (van hoe)). hieu va pham duc van hanh day cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (toc sach)) ky dang ((van hoi) OR (van hoe)). hieu va pham duc van hanh day cua te.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (toc sach)) ky dang ((van hoi) or (van hoe)). hieu va pham duc van hanh day cua te*.