Perhaps you should try some spelling variations:
cham xuc » cam xuc, chat xuc, cham soc
su sach » so sach, vu sach
va hang » van hang, va nang, va lang
va cham » va chat, va tham
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
xuc va » duc va, tuc va, luc va
tai va » thai va, tri va, dai 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 ky ((nang xa) or (nang ma)) hoi. hieu va cham xuc va hang ((tai va) OR (mai va)) thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang xa) OR (nang ma)) hoi. hieu va cham xuc va hang ((tai va) OR (mai va)) thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang xa) or (nang ma)) hoi. hieu va cham xuc va hang ((tai va) OR (mai va)) thiet".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang xa) or (nang ma)) hoi. hieu va cham xuc va hang ((tai va) OR (mai va)) thiet*.