Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
cam thuc » am thuc, nam thuc, cam thu
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
so sach » so sanh, bo sach, co sach
su sach » vu sach
ve cam » ve cham, ve cac, va cam
doi su » don su, voi su
oi su » ki su, vi 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) or (so sach)) ky nang xa hoi. hieu ve cam thuc van hanh ((doi su) OR (oi su)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) ky nang xa hoi. hieu ve cam thuc van hanh ((doi su) OR (oi su)) triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sach)) ky nang xa hoi. hieu ve cam thuc van hanh ((doi su) OR (oi su)) triet*".