Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
tinh lam » trinh lam, dinh lam, tinh lao
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
cho hai » pho hai, co hai, cho bai
van cau » van dau, van hau, van chat
cau duc » cao duc, cau luc, chu duc
va tinh » may tinh
ho hai » hoc hai, pho hai, ho hap
lam su » lai su, lam so, lam vu

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 ty nang ((ho hai) or (cho hai)). hieu van cau duc va tinh lam su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ((ho hai) OR (cho hai)). hieu van cau duc va tinh lam su triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ((ho hai) or (cho hai)). hieu van cau duc va tinh lam su triet*.