If somebody needs I have audioclip with some tongue-twisters:

Белый снег, белый мел, белый заяц — тоже бел, а вот белка не бела, белой даже не была.
White snow, white chalk, white rabbit is white too, but squirrel isn't white, it have never been white.

Иней лег на ветви ели, иглы за ночь побелели.
Hoarfrost has laid down on the fur-tree branches, needles became white in one night

Ехал грека через реку, видит грека — в реке рак, cунул грека руку в реку, рак за руку греку цап!
Грека went across the river, he saw crayfish and try to catch it by his hand. But crayfish cut his hand.

На дворе трава, на траве дрова.
There are grass on the court yard, there are fire wood on the grass.

I can send it to e-mails.