Perhaps you should try some spelling variations:
so sach » so sanh, bo sach, co sach
sach ty » sach y, sach tu, sach thu
ty hang » ly hang, ty xang, thi hang
hieu va » lieu va, hieu qua
truc va » thuc va, thuc vat, trung va
va hanh » van hanh, va thanh, ban hanh
hang o » hang do, hang o2, hoang o
va cau » van cau, va cac, va dau
o hoi » co hoi, o hoc, o hai
vi va » vi van, vai va, vu 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: so sach ty hang o hoi. hieu va cau truc va hanh vi va thiet~.
• Adding a wildcard symbol may retrieve word variants: so sach ty hang o hoi. hieu va cau truc va hanh vi va thiet*.