Tom Apostol's Calculus
This is a classic of mathematics. The .pdfs are made from direct scans of the book. It is divided into two volumes:
Volume I: One-Variable Calculus with an Introduction to Linear Algebra
This book gives architects and designers a working knowledge of architectural acoustics. The control of sound is important not only in obvious places like concert halls, but also in offices where privacy is essential. In Architectural Acoustics, six experienced consultants present basic acoustical principles; specific materials, methods, and techniques for controlling sound in and around buildings; and some recent innovations in acoustical research.
Volume II: Multi-Variable Calculus and Linear Algebra with Applications
Volume II of "Calculus", contained in this work, presents multi-variable calculus and linear algebra, with applications to differential equations and probability.