I. INTRODUCTION

II. LAGRANGIAN FROM HEAVY QUARK SPIN SYMMETRY  
A. Coupling of light vector mesons and heavy mesons  
B. Coupling of light vector mesons and heavy baryons  

III. MOLECULAR STATES FROM RESONANCE-SATURATED CONSTANT INTERACTIONS  
A. Potentials from light vector meson exchange  
B. Poles of molecular states  

IV. DISCUSSIONS OF SELECTED SYSTEMS  
A. Heavy meson-meson molecules vs. doubly heavy tetraquarks  
B. Heavy meson-baryon molecules vs. doubly heavy baryons  
C. Heavy di-baryons  

V. SUMMARY