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