1. Introduction

2. Sample, observations and data reduction
2.1. Sample definition
2.2. Observations and data reduction
2.3. Additional datasets

3. Results
3.2. Multiplicity rate

4. Discussion
4.1. The initial rate of multiple stellar systems
4.2. Distribution of separations: a hint of cloud-to-cloud variation
4.3. Evolution of multiple systems within molecular clouds

5. Conclusion