Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
va trien » va truyen, va thiet, va tuyen
qua tham » qua cham, qua than, qua thanh
tinh vi » trinh vi, tinh voi, tinh va
va tinh » may tinh
thuc va » thuc vat, thuc dan, thuc day
vu sach » vu bach, su sach, vu khach
mang xa » lang xa, mang may, dang xay
so sach » so sanh, bo sach, co sach
nang ma » tang ma, sang ma, nang cao
vi va » vi van, vai va, vu va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sach) or (so sach)) ty ((mang xa) or (nang ma)) hoi. hieu qua tham thuc va tinh vi va trien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (so sach)) ty ((mang xa) OR (nang ma)) hoi. hieu qua tham thuc va tinh vi va trien.
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (so sach)) ty ((mang xa) or (nang ma)) hoi. hieu qua tham thuc va tinh vi va trien*.