Perhaps you should try some spelling variations:
hai chau » lai chau, ha chau, hat chau
nang mai » nang ma, nang tai, lang mai
hieu van » hieu va, thien van, lieu va
cam thuc » am thuc, nam thuc, cam thu
sach ly » sach y, sach lo, sach ty
hoi cau » hoi chu, hoc cau, hoa cau
su sach » so sach, vu sach
van cam » van nam, van lam, van cau
mai hoi » mai khoi, dai hoi, lai hoi
ly nang » ky nang, ly hang, ly vang
va danh » va dinh, va hanh, dia danh
va dan » ca dan, va dao, va dau

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 mai hoi. hieu van cam thuc ((va danh) or (va dan)) ((hoi cau) or (hai chau)) treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ly nang mai hoi. hieu van cam thuc ((va danh) OR (va dan)) ((hoi cau) OR (hai chau)) treo.
• Adding a wildcard symbol may retrieve word variants: su sach ly nang mai hoi. hieu van cam thuc ((va danh) or (va dan)) ((hoi cau) or (hai chau)) treo*.