Perhaps you should try some spelling variations:
nhan mai » nhan tai, nhan dai, nhan mac
hieu van » hieu va, thien van, lieu va
thuc van » thuc vat, thuc dan, thuc va
co viet » so viet, o viet, hoc viet
nhan ma » nhan mac, nhan va, nhan my
van cam » van nam, van lam, van cau
tuc van » truc van, tuc va, duc van
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky
x hoi » xa hoi, o hoi, x ho

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky nang x hoi. hieu van cam ((tuc van) OR (thuc van)) ((nhan mai) OR (nhan ma)) co viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky nang x hoi. hieu van cam ((tuc van) or (thuc van)) ((nhan mai) OR (nhan ma)) co viet~".
• Adding a wildcard symbol may retrieve word variants: su sac ky nang x hoi. hieu van cam ((tuc van) or (thuc van)) ((nhan mai) OR (nhan ma)) co viet*.