Perhaps you should try some spelling variations:
teaching change » teaching chinese, teaching chapter, teaching china
roberto luis » robert louis, roberto out
roberto bin » roberto n, roberto bola
time last » time list, time past, time class
time lost » time cost, time loss, time list
tan yang » dan yang, tan ying, tan yong
yang i » yang di, yang xi, yang yi

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tan yang i ((time last) OR (time lost)) teaching change ((roberto bin) OR (roberto luis)) ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tan yang i ((time last) or (time lost)) teaching change ((roberto bin) OR (roberto luis)) ;~".
• Adding a wildcard symbol may retrieve word variants: tan yang i ((time last) or (time lost)) teaching change ((roberto bin) OR (roberto luis)) ;*.