Perhaps you should try some spelling variations:
thanh tan » thanh toan, thanh tuan, thanh san
toc sach » doc sach, thuoc sach, nuoc sach
tuc thai » thuc thai, toc thai, tuc hai
hoc sach » hoc sinh, hoc cac, hoc anh
thuc tai » thuc thai, thuoc tai, thuc tap
hieu van » hieu va, thien van, lieu va
tan cua » than cua, tang cua, toan cua
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
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: ((toc sach) OR (hoc sach)) ky lang xa hoi. hieu van nam ((tuc thai) or (thuc tai)) thanh tan cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) ky lang xa hoi. hieu van nam ((tuc thai) OR (thuc tai)) thanh tan cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (hoc sach)) ky lang xa hoi. hieu van nam ((tuc thai) or (thuc tai)) thanh tan cua te".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (hoc sach)) ky lang xa hoi. hieu van nam ((tuc thai) or (thuc tai)) thanh tan cua te*.