Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
trinh tu » trinh ky, trinh do
nang xa » nang x, lang xa, nang ma
cuu tre » cua tre, cau tren, cau treo
y nang » ky nang, ly nang, v nang
tu dan » tuc dan, tu ban, tu can
cu dan » cua dan, ca dan, co dan
tu cuu » tu huu, tu cua, tu chu

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 y nang xa hoi. hieu van nam ((tu dan) OR (cu dan)) trinh tu cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang xa hoi. hieu van nam ((tu dan) OR (cu dan)) trinh tu cuu tre".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang xa hoi. hieu van nam ((tu dan) OR (cu dan)) trinh tu cuu tre*.