fWorldCat can be used to identify primary sources. Here are some examples of searches that produce examples of primary sources:
su:Travel, Medieval sources
su:Cities and towns, Medieval sources
su:Voyages and travels Early works to 1800 sources
su: History Sources Florence [or Cairo or Hangzhou etc.] Once you have a record for the time period you want, look at the subjects to see if there is one for the period you want.)
Also try keyword search with chronicle and name of city or country.