Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
phuc van » thuc van, phuc va, chuc van
nang xa » nang x, lang xa, nang ma
tang di » hang di, tang du, tang do
tang da » tang dan, tang dam, tang ma
cua tre » cua te, cuu tre, cua triet
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach v nang xa hoi. hieu ((ke cau) OR (ket cau)) phuc van ((tang di) or (tang da)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach v nang xa hoi. hieu ((ke cau) OR (ket cau)) phuc van ((tang di) OR (tang da)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach v nang xa hoi. hieu ((ke cau) OR (ket cau)) phuc van ((tang di) or (tang da)) cua tre".
• Adding a wildcard symbol may retrieve word variants: hoc sach v nang xa hoi. hieu ((ke cau) OR (ket cau)) phuc van ((tang di) or (tang da)) cua tre*.