Perhaps you should try some spelling variations:
hang khoa » dung khoa
lang khoa » dang khoa, long khoa, vang khoa
su triet » su viet, su tien, ve triet
hanh va » hang va, hanh vi
thuc va » thuc dan, thuc day
hieu ve » hieu va, hieu van
ve nam » he nam, va nam, le nam
sai ky » sac ky
te sai » te tai, te bai, te lai

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: te sai ky ((lang khoa) OR (hang khoa)) hoi. hieu ve nam ((thuc va) OR (thuc vat)) hanh va su triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sai ky ((lang khoa) OR (hang khoa)) hoi. hieu ve nam ((thuc va) or (thuc vat)) hanh va su triet~".
• Adding a wildcard symbol may retrieve word variants: te sai ky ((lang khoa) OR (hang khoa)) hoi. hieu ve nam ((thuc va) or (thuc vat)) hanh va su triet*.