Perhaps you should try some spelling variations:
chat hoc » chat hoa, chat thom, cho hoc
cam thuc » am thuc, nam thuc, cam thu
tu sach » thu sach, su sach, te sach
cao hoc » co hoc, cho hoc
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
su hien » su kien, su tien, thu hien
y nang » ky nang, ly nang, v nang
va cam » va cham, va cac, va cao
vi su » va su, ve su, ki su

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y nang ((cao hoc) or (chat hoc)). lieu va cam thuc va hanh vi su hien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((cao hoc) OR (chat hoc)). lieu va cam thuc va hanh vi su hien.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((cao hoc) or (chat hoc)). lieu va cam thuc va hanh vi su hien*.