Perhaps you should try some spelling variations:
cau trieu » cac trieu, cau triet, chua trieu
nang mai » nang ma, nang tai, lang mai
hieu van » hieu va, thien van, lieu va
cam thuc » am thuc, nam thuc, can thuc
lanh hai » manh hai, thanh hai, lang chai
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
mai hoi » mai khoi, dai hoi, lai hoi
cam thu » nam thu, cac thu, ca thu
va lanh » va lang, 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 mai hoi. hieu van ((cam thuc) or (cam thu)) va lanh hai cau trieu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang mai hoi. hieu van ((cam thuc) OR (cam thu)) va lanh hai cau trieu.
• Adding a wildcard symbol may retrieve word variants: su sach ky nang mai hoi. hieu van ((cam thuc) or (cam thu)) va lanh hai cau trieu*.