Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
nang mai » nang ma, nang tai, lang mai
tinh hai » tinh thai, tinh chat, trinh han
tinh dai » trinh dai, tinh da, tinh doi
sach ty » sach y, sach tu, sach thu
su sach » so sach, vu sach
cac luc » cau luc, coc luc, cac nuoc
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
ty nang » ky nang, ty xang, ty hang
ve cac » va cac, vien cac
cua te » cua tu
luc va » duc va, tuc va, loc va

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 mai hoi. hieu ve cac luc va ((tinh dai) OR (tinh hai)) ((cua te) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang mai hoi. hieu ve cac luc va ((tinh dai) OR (tinh hai)) ((cua te) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty nang mai hoi. hieu ve cac luc va ((tinh dai) OR (tinh hai)) ((cua te) or (cua triet))".
• Adding a wildcard symbol may retrieve word variants: su sach ty nang mai hoi. hieu ve cac luc va ((tinh dai) OR (tinh hai)) ((cua te) or (cua triet))*.