Perhaps you should try some spelling variations:
phan mai » phan dai, phan may, phan bai
su sach » vu sach
so sach » so sanh, bo sach, co sach
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
va phan » van phan, va phat, va phap
va cam » va cham, va cac, va cao
xuc va » duc va, tuc va, luc va
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) OR (so sach)) ky ((nang xa) or (nang ma)) hoi. hieu va cam xuc va phan mai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) ky ((nang xa) OR (nang ma)) hoi. hieu va cam xuc va phan mai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (so sach)) ky ((nang xa) or (nang ma)) hoi. hieu va cam xuc va phan mai va thiet".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (so sach)) ky ((nang xa) or (nang ma)) hoi. hieu va cam xuc va phan mai va thiet*.