But the "references" in Euler seem to be close to references nowadays. There is no access to the address, no pointer arithmetic etc. such as in PL/I.
Euler had both an address-of operator, which was prefix "@" and an indirect addressing a.k.a. pointer dereferencing operator, which was a postfix middle dot.
So it had everything that C has, except pointer arithmetic.
Only a subset of the programming languages that have pointers also allow pointer arithmetic, because many believe that whenever address arithmetic is needed only indices shall be used, not pointers, because with indices it is much easier for the compiler to determine the range of addresses that may be accessed.