Complex sentence: Pieter van Laer was possibly a pupil of Esaias van de Velde in Haarlem as his early work, in particular a drawing signed Pieter Bodink (formerly in the collection of A. Welcker), shows his closeness to this artist.
Split into simpler sentences: Pieter van Laer was possibly a pupil of Esaias van de Velde in Haarlem as his early work. Evidence for this is a drawing signed Pieter Bodink (formerly in the collection of A. Welcker), which shows his closeness to this artist.