Perhaps you should try some spelling variations:
sach tham » sach nha
tham nang » nham nang, tham lang, tham nhung
cham thuc » nham thuc, pham thuc, tham thuc
sinh thai » dinh thi
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
te sach » toc sach
mai hoi » mai khoi, dai hoi, lai hoi
thuc va » thuc vat, thuc dan, thuc day
va sinh » va kinh, va tinh, vi sinh
thai va » thai van
ma hoi » xa hoi, ma hoa, me hoi
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: te sach tham nang ((ma hoi) or (mai hoi)). hieu van cham thuc va sinh thai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach tham nang ((ma hoi) OR (mai hoi)). hieu van cham thuc va sinh thai va thiet.
• Adding a wildcard symbol may retrieve word variants: te sach tham nang ((ma hoi) or (mai hoi)). hieu van cham thuc va sinh thai va thiet*.