Perhaps you should try some spelling variations:
sach tham » sach nha
cach thuc » anh thuc, cac thu
han tai » hang tai, nhan tai, van tai
ve cham » va cham, ve chat, vu cham
hieu ve » hieu va, hieu van
tang ma » mang may, tang van
ma hoi » mai hoi, xa hoi, ma hoa
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa
tai va » thai va, mai va, tri 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 ((cach thuc) or (sach tham)) tang ma hoi. hieu ve cham ((xuc va) OR (tuc va)) han tai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((cach thuc) OR (sach tham)) tang ma hoi. hieu ve cham ((xuc va) OR (tuc va)) han tai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((cach thuc) or (sach tham)) tang ma hoi. hieu ve cham ((xuc va) OR (tuc va)) han tai va thiet".
• Adding a wildcard symbol may retrieve word variants: tu ((cach thuc) or (sach tham)) tang ma hoi. hieu ve cham ((xuc va) OR (tuc va)) han tai va thiet*.