Perhaps you should try some spelling variations:
sach thue » sach thu, sach thieu, sach tham
va trien » va truyen, va thiet, va tuyen
cam thuc » am thuc, nam thuc, cam thu
hieu van » hieu va, thien van, lieu va
tinh gi » tinh gia, sinh gi, tinh vi
va tinh » may tinh
thuc va » thuc vat, thuc dan, thuc day
van cam » van nam, van lam, van cau
sach ty » sach y, sach tu, sach thu
sang ma » tang ma, nang ma, sang tao
nang xa » nang x, lang xa, nang ma
gi va » bi va, gi la, gi ta

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 ty) or (sach thue)) ((nang xa) or (sang ma)) hoi. hieu van cam thuc va tinh gi va trien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach thue)) ((nang xa) OR (sang ma)) hoi. hieu van cam thuc va tinh gi va trien.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sach thue)) ((nang xa) or (sang ma)) hoi. hieu van cam thuc va tinh gi va trien*.