Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
gian cua » gian xu, ban cua
hoc sach » hoc sinh, hoc cac, hoc anh
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
cac toc » cac toi, cac thoi
van dan » van ban, ban dan, van dao
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
cua tu » cua tuc, cua su, cua cu

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 sach)) ky lang xa hoi. hieu va ((cac toc) or (cac nuoc)) van dan gian cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) ky lang xa hoi. hieu va ((cac toc) OR (cac nuoc)) van dan gian cua tu*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (hoc sach)) ky lang xa hoi. hieu va ((cac toc) or (cac nuoc)) van dan gian cua tu*".