Perhaps you should try some spelling variations:
"open generalized sturm" » "open generalized schur", "open generalized state", "open generalized stokes", "en generalized sturm", "span generalized sturm", "upon generalized sturm"
"chen generalized sturm" » "chen generalized schur", "chen generalized state", "chen generalized stokes", "when generalized sturm", "chain generalized sturm", "en generalized sturm"

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