Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
toc sach » hoc sach, doc sach, thuoc sach
truc may » tren may, truc va
cam truc » cau truc, nam truc, lam truoc
sach ky » sac ky, sach y, sach ty
tinh ve » trinh ve, tinh ven, dinh ve
hieu ve » hieu va, hieu van
tay hoi » tao hoi, tay thai
ky dang » ky nang, ky danh
su tien » su kien, su hien, tu tieng
ve cam » ve cham, ve cac, va cam
tay ho » tay co, tay o, tay khao

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky dang ((tay hoi) or (tay ho)). hieu ve cam truc may tinh ve ((cua triet) or (su tien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky dang ((tay hoi) OR (tay ho)). hieu ve cam truc may tinh ve ((cua triet) OR (su tien)).
• Adding a wildcard symbol may retrieve word variants: toc sach ky dang ((tay hoi) or (tay ho)). hieu ve cam truc may tinh ve ((cua triet) or (su tien))*.