Lessons 28–29 · 2 lessons · B. To‘xliyev, B. Karimov, K. Usmonova. Literature: textbook-collection for Grade 11 of secondary schools and for students of secondary specialised and vocational institutions, Parts 1–2. 1st edition. “O‘zbekiston milliy ensiklopediyasi” State Scientific Publishing House, Tashkent, 2018