Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
hieu van » hieu va, thien van, lieu va
danh hai » dang hai, lanh hai, manh hai
cam thuc » am thuc, nam thuc, cam thu
mai hoi » mai khoi, dai hoi, lai hoi
sach ly » sach y, sach lo, sach ty
van cam » van nam, van lam, van cau
thuc va » thuc vat, thuc dan, thuc day
va danh » va dinh, va dan, va hanh
ly nang » ky nang, ly hang, ly vang
hai cau » hai chau, hai chu, hai hau
su sach » so sach, vu sach
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 ly nang ((ma hoi) or (mai hoi)). hieu van cam thuc va danh hai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ly nang ((ma hoi) OR (mai hoi)). hieu van cam thuc va danh hai cau tren.
• Adding a wildcard symbol may retrieve word variants: su sach ly nang ((ma hoi) or (mai hoi)). hieu van cam thuc va danh hai cau tren*.