Show the names of donors who donated to both school "Glenn" and "Triton"
select t1.donator_name from endowment as t1 join school as t2 on t1.school_id = t2.school_id where t2.school_name = 'Glenn' intersect select t1.donator_name from endowment as t1 join school as t2 on t1.school_id = t2.school_id where t2.school_name = 'Triton'