I'm looking for sesame street episodes

[Sesamo2012]

Hello Im a college teacher in Chicago IL teaching class called Forbidden Past a tribute to children education. does any one out thier in the world of sesame street knowledge know were to find these episodes that I'M looking for to use in my class on our subject on sesame street, the episodes are

1. Episode 2874( a day in Birdland)

2.episode 2587

3. Episode 1200) from 1970 to 80?

so far have nothing to trade either from sesame street only 2282, and stuff from Noggin, but people may not want the noggin stuff, but any one has those episodes and is willing to either make a copy for me or have them email here or let me know how much it costs to buy. thanks and have a good day.