Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
nam thuc » nam thuoc, am thuc, nam thu
va thanh » gia thanh, ban thanh, va tinh
va hanh » van hanh, va danh, ban hanh
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
van hoi » van hoa, van hoc, van hoe
y nang » ky nang, ly nang, may nang
v nang » va nang, vu nang, van nang
va nam » van nam, ha nam, va nay
vi su » va su, ve su, ki 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 ((y nang) OR (v nang)) van hoi. hieu va nam thuc ((va hanh) or (va thanh)) vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((y nang) OR (v nang)) van hoi. hieu va nam thuc ((va hanh) OR (va thanh)) vi su triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((y nang) OR (v nang)) van hoi. hieu va nam thuc ((va hanh) or (va thanh)) vi su triet*".