Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
lang hai » lang chai, lang thai, lang ha
cam thuc » am thuc, nam thuc, cam thu
hieu van » hieu va, thien van, lieu va
hai cau » hai chau, hai chu, hai hau
va lang » va nang, hoa lang
thuc va » thuc vat, thuc dan, thuc day
van cam » van nam, van lam, van cau
su sach » so sach
ly nang » ky nang, ly hang, ly vang
vu sach » vu bach, vu khach
mai hoi » mai khoi, dai hoi, lai hoi
ma hoi » xa hoi, ma hoa, me hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (vu sach)) ly nang ((ma hoi) or (mai hoi)). hieu van cam thuc va lang hai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) ly nang ((ma hoi) OR (mai hoi)). hieu van cam thuc va lang hai cau tren.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu sach)) ly nang ((ma hoi) or (mai hoi)). hieu van cam thuc va lang hai cau tren*.