How to use an SSD1603 (oled 0.96'') with Attiny85

Other Hardware Displays
10

Ok, now the sketch is:
#include <Arduino.h>
#include <U8x8lib.h>
U8X8_SSD1306_128X64_NONAME_SW_I2C u8x8(7,5,1);
void setup(void) {
u8x8.begin();
}
void loop(void) {
u8x8.setFont(u8x8_font_chroma48medium8_r);
u8x8.drawString(0,0,"Hello World!");
delay(1000);
}

But there are still errors...
sketch_nov22a:4: error: 'U8X8_SSD1306_128X64_NONAME_SW_I2C' does not name a type
sketch_nov22a.ino: In function 'void setup()':
sketch_nov22a:7: error: 'u8x8' was not declared in this scope
sketch_nov22a.ino: In function 'void loop()':
sketch_nov22a:11: error: 'u8x8' was not declared in this scope
sketch_nov22a:11: error: 'u8x8_font_chroma48medium8_r' was not declared in this scope