Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
cau tren » cu tren, dau tren, ca tren
cua viet » ca viet, hoa viet, cua vat
sach ky » sac ky, sach y, sach ty
ve pham » vi pham, v pham, ve phat
ve phan » va phan, ke phan, ve phat
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach ky nang o hoi. hieu ((ve pham) or (ve phan)) duc va hanh di ((cau tren) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ky nang o hoi. hieu ((ve pham) OR (ve phan)) duc va hanh di ((cau tren) OR (cua viet)).
• Adding a wildcard symbol may retrieve word variants: thuat sach ky nang o hoi. hieu ((ve pham) or (ve phan)) duc va hanh di ((cau tren) or (cua viet))*.