Perhaps you should try some spelling variations:
thanh nam » hanh nam, thanh tam, thanh pham
nang hoa » nang hoat, hang hoa, nang hoc
hieu van » hieu va, thien van, lieu va
va thanh » gia thanh, ban thanh, va tinh
su triet » su viet, su tien, ve triet
vu sach » vu bach, su sach, vu khach
co sach » bo sach, cuon sach, hoc sach
cac duc » cao duc, cac dac, cac nuoc
nam su » nam suu, nam sau, nam so

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sach) or (co sach)) ky nang hoa hoc. hieu van ((cac duc) OR (cac du)) va thanh nam su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (co sach)) ky nang hoa hoc. hieu van ((cac duc) OR (cac du)) va thanh nam su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (co sach)) ky nang hoa hoc. hieu van ((cac duc) OR (cac du)) va thanh nam su triet".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (co sach)) ky nang hoa hoc. hieu van ((cac duc) OR (cac du)) va thanh nam su triet*.