Perhaps you should try some spelling variations:
when class » open class, within class
class john » class jobs
wang yang » wang yan, wang liang, wang yanling
yang yang » wang yan
wong siu » wong shiu, wong sau, wong siew
kong siu » kong eiu, dong sin, kong sar
yang a » yang ka, yang _, yang 8
a when » 3 when, 4 when, 1 when

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

• Performing a fuzzy search may retrieve terms with similar spellings: wang yang yang a when class john ((wong siu) or (kong siu)) ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wang yang yang a when class john ((wong siu) OR (kong siu)) ;.
• Adding a wildcard symbol may retrieve word variants: wang yang yang a when class john ((wong siu) or (kong siu)) ;*.