The statement that cloud forms grow through condensation, convection, and atmospheric lifting is a standard and well-established textbook definition in meteorology and does not require a citation.
The claim outlines fundamental, foundational meteorological processes taught in introductory physics and earth sciences regarding cloud formation (thermodynamics, condensation nuclei, moist convection, and adiabatic cooling via lifting). Per instructions, trivially true definitions and standard descriptions of everyday or textbook scientific observations are classified as COMMON_KNOWLEDGE, requiring no papers and yielding empty indices.