The best way to do that is using table aliases and column aliases as below
for one column:
SELECT ref1.frubberducks
FROM table1 ref1,table1 ref2,table2 ref3,table2 ref4,table3
WHERE ref3.a = ref1.b and ref4.a = ref2.b and ref3.c=f and ref4.c=d
for two columns with the same name:
SELECT ref1.frubberducks,
ref2.frubberducks
FROM table1 ref1,table1 ref2,table2 ref3,table2 ref4,table3
WHERE ref3.a = ref1.b and ref4.a = ref2.b and ref3.c=f and ref4.c=d
for two columns with the same name and with column aliases:
SELECT ref1.frubberducks ref1frubberducks,
ref2.frubberducks ref2frubberducks
FROM table1 ref1,table1 ref2,table2 ref3,table2 ref4,table3
WHERE ref3.a = ref1.b and ref4.a = ref2.b and ref3.c=f and ref4.c=d