Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
lang hai » lang chai, lang thai, lang ha
vat lang » va lang, van lang, vat mang
cam thuc » am thuc, nam thuc, cam thu
hieu van » hieu va, thien van, lieu va
mai hoi » mai khoi, dai hoi, lai hoi
hai cau » hai chau, hai chu, hai hau
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
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 vat 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 vat 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 vat lang hai cau tren*.