Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
thai cua » than cua, tai cuc, tri cua
han thai » han tai, ban thai, van thai
hieu van » hieu va, thien van, lieu va
truc va » thuc va, thuc vat, trung va
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
tuc va » thuc va, tuc xa, duc va
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 sinh)) ky dang xa hoi. hieu van nam ((tuc va) OR (truc va)) han thai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sinh)) ky dang xa hoi. hieu van nam ((tuc va) OR (truc va)) han thai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) or (hoc sinh)) ky dang xa hoi. hieu van nam ((tuc va) OR (truc va)) han thai cua te".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (hoc sinh)) ky dang xa hoi. hieu van nam ((tuc va) OR (truc va)) han thai cua te*.