Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
nam thuc » nam thuoc, am thuc, nam thu
dam phan » d phan, va phan, van phan
day phan » duy phan, dan phan, data phan
nang hoc » nang doc, nang luc, dong hoc
lap cua » lai cua, tap cua, lam cua
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
nang ho » nang co, tang ho, nang cao
hieu vu » hieu va, hieu ve, hieu su
vu nam » su nam, tu nam, va nam

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 ty ((nang ho) or (nang hoc)) hoi. hieu vu nam thuc ((day phan) OR (dam phan)) lap cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((nang ho) OR (nang hoc)) hoi. hieu vu nam thuc ((day phan) OR (dam phan)) lap cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty ((nang ho) or (nang hoc)) hoi. hieu vu nam thuc ((day phan) OR (dam phan)) lap cua triet".
• Adding a wildcard symbol may retrieve word variants: su sach ty ((nang ho) or (nang hoc)) hoi. hieu vu nam thuc ((day phan) OR (dam phan)) lap cua triet*.