Blanks in my family tree, HELP?

All-

I am recreating my family tree. Most of the information is packed away after subsequent moves. My name is Robert Tripp,father is Leslie Charles Tripp, grandmother is Evelyn Bernice Haas, and my gr-gr grandfather is John Frank Haas. John Frank Haas married Murna Erma Linn and I have Murna's parents being Alexander Speare Linn and Ida Elizabeth Fast. Sorry, I have no dates past my father. The Haas' lived in the midwest and my father was born in Des Moines.

Hope this helps and I hope it gives me some insight. I am thinking that my grandmother was born in 1928.

Regards,
Rob Tripp
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