Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cam thuc » am thuc, nam thuc, cam thu
manh hai » lanh hai, minh hai, thanh hai
cau tren » cu tren, dau tren, ca tren
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
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 manh » van manh, va danh, va hanh
hai cau » hai chau, hai chu, hai hau

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 ky ((nang xa) OR (nang ma)) hoi. hieu van cam thuc va manh hai cau tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang xa) OR (nang ma)) hoi. hieu van cam thuc va manh hai cau tren".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang xa) OR (nang ma)) hoi. hieu van cam thuc va manh hai cau tren*.