Alkali metals doped cycloparaphenylene nanohoops: Promising nonlinear optical materials with enhanced performance - Ruqiya Rasul; Tariq Mahmood; Khurshid Ayub; Khurram Saleem Joya; Farooq Anwar; Nazamid Saari; R. Nawaz; Mazhar Amjad Gilani (Heliyon, 2023)