Perhaps you should try some spelling variations:
dang xay » dang van, van xay
tinh doi » trinh doc, trinh do, tinh hoc
su triet » su viet, su tien, ve triet
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
cac tuc » cac toc, cac tac, cac nuoc
va tinh » may tinh
cac tu » cac thu, cach tu, cac du
doi su » oi su, don su, voi su

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky ((nang xa) or (dang xay)) hoi. lieu va ((cac tuc) or (cac tu)) va tinh doi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang xa) OR (dang xay)) hoi. lieu va ((cac tuc) OR (cac tu)) va tinh doi su triet.
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang xa) or (dang xay)) hoi. lieu va ((cac tuc) or (cac tu)) va tinh doi su triet*.