Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cam thuc » am thuc, nam thuc, cam thu
tinh nha » trinh nha, tinh ha, hinh nha
su sach » so sach, vu sach
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
van cam » van nam, van lam, van cau
thuc va » thuc vat, thuc dan, thuc day
va tinh » may tinh
nha cua » nhat cua, nhan cua, nghia cua
cua tre » cua te, cuu tre, cua triet

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 y ((nang xa) or (nang ma)) hoi. hieu van cam thuc va tinh nha cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y ((nang xa) OR (nang ma)) hoi. hieu van cam thuc va tinh nha cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach y ((nang xa) or (nang ma)) hoi. hieu van cam thuc va tinh nha cua tre*.