Perhaps you should try some spelling variations:
xanh hanh » danh thanh, ban hanh, van hanh
manh hanh » danh thanh, minh thanh, manh huynh
pham duy » pham duc
thu nang » thi nang, thu hang, thu bang
hieu van » hieu va, thien van, lieu va
van pham » san pham, van phan, van phat
sach thu » sach thue, sach thieu, sach tham
tu sach » thu sach, su sach, te sach
ca viet » va viet, co viet, hoa viet
lai ca » lai cua, lai cam, loai ca
x hoi » o hoi, x ho, 5 hoi

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 thu nang ((x hoi) OR (xa hoi)). hieu van pham duy ((manh hanh) or (xanh hanh)) lai ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thu nang ((x hoi) OR (xa hoi)). hieu van pham duy ((manh hanh) OR (xanh hanh)) lai ca viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach thu nang ((x hoi) OR (xa hoi)). hieu van pham duy ((manh hanh) or (xanh hanh)) lai ca viet".
• Adding a wildcard symbol may retrieve word variants: tu sach thu nang ((x hoi) OR (xa hoi)). hieu van pham duy ((manh hanh) or (xanh hanh)) lai ca viet*.