Perhaps you should try some spelling variations:
changes taking » changes lacking, change making, change speaking
test changes » net changes, past changes, detect changes
taking level » making level, taking leave, teaching level
wang yang » wang yan, wang liang
lanka 3.1 » lanka 9.1, lanka 11.1, lankas 3.4
3.1 test » 4.1 test
yeung » young

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((wang yanling) OR (wang yang)) lanka 3.1 test changes taking level yeung ;~".
• Adding a wildcard symbol may retrieve word variants: ((wang yanling) OR (wang yang)) lanka 3.1 test changes taking level yeung ;*.