Perhaps you should try some spelling variations:
sach thi » sach thu, sach tai, sach thieu
thi hanh » thi thanh
nhiem va » nghiem va, hiem xa
tu sach » thu sach, su sach, te sach
hanh xa » hanh va, hanh ma, hanh xu
hieu ve » hieu va, hieu van
cau luc » cau truc, cau phuc
va hanh » van hanh, va thanh, va danh
ve cau » ke cau, va cau, ve cac
luc va » duc va, tuc va, loc va
kem va » kiem va, kiem van
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 thi hanh xa hoi. hieu ve cau luc va hanh ((kem va) or (nhiem va)) thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thi hanh xa hoi. hieu ve cau luc va hanh ((kem va) OR (nhiem va)) thiet.
• Adding a wildcard symbol may retrieve word variants: tu sach thi hanh xa hoi. hieu ve cau luc va hanh ((kem va) or (nhiem va)) thiet*.