Perhaps you should try some spelling variations:
sach kem » hanh kem
hieu va » lieu va, hieu qua
va cham » va chat, va tham
nang xa » nang x, lang xa, nang ma
su viet » so viet
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa
vi su » va su, ve su, ki su

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 kem) or (sach y)) nang xa hoi. hieu va cham ((xuc va) or (tuc va)) hanh vi su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach kem) OR (sach y)) nang xa hoi. hieu va cham ((xuc va) OR (tuc va)) hanh vi su viet.
• Adding a wildcard symbol may retrieve word variants: su ((sach kem) or (sach y)) nang xa hoi. hieu va cham ((xuc va) or (tuc va)) hanh vi su viet*.