Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
van nham » van nam, van nhan, van tham
vat danh » van danh, luat danh, nhat danh
hoc cac » hoc cao
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
va danh » va dinh, va dan, va hanh
cuu tre » cua tre, cau tren, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) or (hoc cac)) ky lang xa hoi. hieu van nham thuc ((vat danh) OR (va danh)) sai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc cac)) ky lang xa hoi. hieu van nham thuc ((vat danh) OR (va danh)) sai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) or (hoc cac)) ky lang xa hoi. hieu van nham thuc ((vat danh) OR (va danh)) sai cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (hoc cac)) ky lang xa hoi. hieu van nham thuc ((vat danh) OR (va danh)) sai cuu tre*.