Perhaps you should try some spelling variations:
vat thanh » gat thanh, tat thanh, viet thanh
dat thanh » dao thanh, dat khanh, dang thanh
cua triet » cua viet, su triet, va triet
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
y nang » ky nang, ly nang, v nang
de cua » le cua, te cua, dieu cua
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach y nang x hoi. hieu van nam thuc ((vat thanh) OR (dat thanh)) de cua triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach y nang x hoi. hieu van nam thuc ((vat thanh) OR (dat thanh)) de cua triet".
• Adding a wildcard symbol may retrieve word variants: thu sach y nang x hoi. hieu van nam thuc ((vat thanh) OR (dat thanh)) de cua triet*.