Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
lang van » dang van, tang van, hoang van
hanh vai » hanh vi, hanh va, hanh tai
cua viet » ca viet, hoa viet, cua vat
su triet » su viet, su tien, ve triet
sach ky » sac ky, sach y, sach ty
cac lop » cac hop, cac loai
va hanh » van hanh, va thanh, va danh
lop va » lap va, hop va, nop va

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky ((nang x) or (lang van)) hoi. lieu va cac lop va hanh vai ((cua viet) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((nang x) OR (lang van)) hoi. lieu va cac lop va hanh vai ((cua viet) OR (su triet)).
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((nang x) or (lang van)) hoi. lieu va cac lop va hanh vai ((cua viet) or (su triet))*.