Find the name of the scientist who worked on both a project named 'A Matter of Time' and a project named 'A Puzzling Parallax'.
select t3.name from assignedto as t1 join projects as t2 on t1.project = t2.code join scientists as t3 on t1.scientist = t3.ssn where t2.name = 'Matter of Time' intersect select t3.name from assignedto as t1 join projects as t2 on t1.project = t2.code join scientists as t3 on t1.scientist = t3.ssn where t2.name = 'A puzzling Parallax'