Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
vat hanh » vat thanh, van hanh, va hanh
sach ky » sac ky, sach y, sach ty
ve pham » vi pham, v pham, ve phat
ve phan » va phan, ke phan, ve phat
hanh di » hanh vi, hanh de, hang di
co hoi » co loi
di cua » dai cua, doi cua, de cua
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: thu sach ky nang ((co hoi) OR (co hoc)). hieu ((ve pham) or (ve phan)) thuc vat hanh di cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang ((co hoi) OR (co hoc)). hieu ((ve pham) OR (ve phan)) thuc vat hanh di cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang ((co hoi) OR (co hoc)). hieu ((ve pham) or (ve phan)) thuc vat hanh di cua te".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang ((co hoi) OR (co hoc)). hieu ((ve pham) or (ve phan)) thuc vat hanh di cua te*.