Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van pham » san pham, van phan, van phat
van hanh » van thanh, ban hanh, van anh
va trien » va truyen, va thiet, va tuyen
tu sach » thu sach, su sach, te sach
duc van » duc va, duc tan, duc manh
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, me hoi
vi va » vi van, vai va, vu va

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 y nang ((ma hoi) OR (ma hoa)). hieu van pham duc van hanh vi va trien~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang ((ma hoi) OR (ma hoa)). hieu van pham duc van hanh vi va trien".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((ma hoi) OR (ma hoa)). hieu van pham duc van hanh vi va trien*.