"Primer on the Metabolic Bone Diseases and Disorders of Mineral Metabolism" by Ed Murray J Favus is the second edition of a multi-author publication by the American Society for Bone and Mineral Research. The book is divided into short chapters by over 80 authors and covers most disorders of bone and mineral metabolism. While there is some overlap and variation in style and referencing, the book provides a good balance and is a useful primer for students, physicians, and scientists seeking a brief overview of bone metabolism. It is aimed mainly at American readers and may have some limitations in other regions due to differences in treatment approaches and terminology. Despite these issues, the book is well-structured and recommended for those with an interest in bone disease. "Dubois' Lupus Erythematosus," the fourth edition edited by D J Wallace and B H Hahn, is a comprehensive and well-written textbook on lupus. It has been expanded with more contributors and chapters, and the style is highly readable with a comprehensive bibliography. However, it contains some Americanisms that may be unfamiliar to European readers. The management sections are strong, but some treatment recommendations, such as the dismissal of methotrexate, are considered premature. Despite these minor issues, the book is a valuable resource for rheumatologists. Both books are highly recommended for their respective fields."Primer on the Metabolic Bone Diseases and Disorders of Mineral Metabolism" by Ed Murray J Favus is the second edition of a multi-author publication by the American Society for Bone and Mineral Research. The book is divided into short chapters by over 80 authors and covers most disorders of bone and mineral metabolism. While there is some overlap and variation in style and referencing, the book provides a good balance and is a useful primer for students, physicians, and scientists seeking a brief overview of bone metabolism. It is aimed mainly at American readers and may have some limitations in other regions due to differences in treatment approaches and terminology. Despite these issues, the book is well-structured and recommended for those with an interest in bone disease. "Dubois' Lupus Erythematosus," the fourth edition edited by D J Wallace and B H Hahn, is a comprehensive and well-written textbook on lupus. It has been expanded with more contributors and chapters, and the style is highly readable with a comprehensive bibliography. However, it contains some Americanisms that may be unfamiliar to European readers. The management sections are strong, but some treatment recommendations, such as the dismissal of methotrexate, are considered premature. Despite these minor issues, the book is a valuable resource for rheumatologists. Both books are highly recommended for their respective fields.