Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
doc sach » hoc sach, nuoc sach, dac sac
phan lap » phan dau
tao khoi » thao khoa, lao khoa, tao boi
lap cua » lai cua, tap cua, lam cua
ky sang » ky nang, ky dang, ky tang
tao hoi » tao boi, tay hoi, thao hoc
va phan » van phan, va phat, va phap
v pham » vi pham, d pham
cua te » cua tu
hieu v » hieu va, hieu ve, hieu 2

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) or (doc sach)) ky sang ((tao hoi) OR (tao khoi)). hieu v pham duc va phan lap cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ky sang ((tao hoi) OR (tao khoi)). hieu v pham duc va phan lap cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) or (doc sach)) ky sang ((tao hoi) OR (tao khoi)). hieu v pham duc va phan lap cua te".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (doc sach)) ky sang ((tao hoi) OR (tao khoi)). hieu v pham duc va phan lap cua te*.