Perhaps you should try some spelling variations:
sach truc » cach thuc, sach tren, sach thu
sach tru » sach thu, sach tu, sach tren
toc cham » toc thai
danh de » hanh de, dan de, dang de
va danh » va dinh, va dan, va hanh
tu cham » thi cham
su viet » so viet
x hoi » xa hoi, o hoi, x ho
de su » den su, ve su, de tu

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 tru) or (sach truc)) nang x hoi. hieu ((tu cham) or (toc cham)) duc va danh de su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach tru) OR (sach truc)) nang x hoi. hieu ((tu cham) OR (toc cham)) duc va danh de su viet.
• Adding a wildcard symbol may retrieve word variants: tu ((sach tru) or (sach truc)) nang x hoi. hieu ((tu cham) or (toc cham)) duc va danh de su viet*.