Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
lang van » dang van, tang van, hoang van
dang xay » dang van, van xay
cac truc » cau truc, cac tru, cac trung
truc van » truc va, thuc van, truc ban
van hanh » van thanh, ban hanh, van anh
hieu ve » hieu va, hieu van
cua tuc » cua duc, cua tu, cua thuoc
ve cac » va cac, vien cac
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 y ((lang van) or (dang xay)) hoi. hieu ve cac truc van hanh vi ((cua tuc) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y ((lang van) OR (dang xay)) hoi. hieu ve cac truc van hanh vi ((cua tuc) OR (cua te)).
• Adding a wildcard symbol may retrieve word variants: toc sach y ((lang van) or (dang xay)) hoi. hieu ve cac truc van hanh vi ((cua tuc) or (cua te))*.