“…The most common length of time was 2 weeks (11 articles, 39%) [ 21 , 26–28 , 36 , 37 , 41 , 45 , 46 , 48 ]. 9 articles did not specify the length of the trip (14%) [ 12 , 18 , 29 , 34 , 39 , 41 , 44 , 47 , 49 ].
20 articles (69%) describe short-term trips that are recurring (return to the same location more than once) either annually, biannually, or at an unspecified periodicity [ 12 , 21 , 26–32 , 34–37 , 39 , 41 , 44 , 46 , 47 ].…”