Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
pham duy » pham duc
cham duc » pham duc, cham soc, phan duc
hieu ve » hieu va
nang xa » nang x, lang xa, nang ma
va hanh » van hanh, va thanh, va danh
hanh du » hanh dua, hanh tu, hanh de
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
du hoa » duc hoa, do hoa, du hoc

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