Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
toc sach » hoc sach, doc sach, thuoc sach
dan cua » dan ca, ban cua, dai cua
dan dan » dang dan, ban dan, dao dan
cac toi » cac thoi
cac toc » cac nuoc, cac thoi
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
va dan » ca dan, va dao, va dau
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) OR (toc sach)) ky lang xa hoi. hieu van ((cac toc) or (cac toi)) va dan dan cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky lang xa hoi. hieu van ((cac toc) OR (cac toi)) va dan dan cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ky lang xa hoi. hieu van ((cac toc) or (cac toi)) va dan dan cua te*".