Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
sach dao » lanh dao
va thanh » gia thanh, ban thanh, va tinh
van hanh » van thanh, ban hanh, van anh
nam thuc » nam thuoc, am thuc, nam thu
cam thuc » am thuc, cam thu, can thuc
dao nang » cao nang, da nang, dai nang
hieu ve » hieu va, hieu van
su sach » so sach, vu sach
x hoi » xa hoi, o hoi, x ho
ki su » ky su

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 dao nang x hoi. hieu ve ((cam thuc) or (nam thuc)) ((van hanh) or (va thanh)) ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach dao nang x hoi. hieu ve ((cam thuc) OR (nam thuc)) ((van hanh) OR (va thanh)) ki su triet.
• Adding a wildcard symbol may retrieve word variants: su sach dao nang x hoi. hieu ve ((cam thuc) or (nam thuc)) ((van hanh) or (va thanh)) ki su triet*.